Planets

Pluto, King of the Underworlds

milhayser — Thu, 30 Jul 2015 12:37:02 +0000

Pluto, King of the Underworlds

New measurements from NASA's New Horizons spacecraft revealed that Pluto, named for the Greco-Roman god once called Hades, is a little more swollen with ice than previously thought, making it the biggest trans-Neptunian object—more voluminous than rival dwarf planet Eris, which is nevertheless more massive. Greg Laden explains why these orbs are not considered full-fledged planets on his blog.

While Eris orbits the Sun within the 'scattered disc,' Pluto orbits in the Kuiper Belt, a collection of gravelly snowballs that Ethan Siegel says outnumber all the planets in our galaxy. The Kuiper Belt begins beyond Neptune, encircling all the planets in our solar system and extending outward for a distance equal to the gap between the Sun and Uranus. It took New Horizons more than nine years to fly to Pluto from Earth, after setting a record for highest launch speed of any man-made object, after getting a massive speed boost from the gravity of Jupiter, and without any need to slow back down. It will now take sixteen months for New Horizons to stream all the scientific data from its brief flyby of Pluto back to Earth. Meanwhile the spacecraft will attempt to visit another smaller Kuiper Belt object before it runs out of fuel and falls short of the edge of our solar system.

milhayser Thu, 07/30/2015 - 08:37

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Misc

Dwarf Planets

Eris

Kuiper Belt

Trans-Neptunian Objects

Uranus

Why there are (and should be) eight planets in the Solar System

esiegel — Wed, 27 Nov 2013 17:03:35 +0000

Why there are (and should be) eight planets in the Solar System

“I have announced this star as a comet, but since it is not accompanied by any nebulosity and, further, since its movement is so slow and rather uniform, it has occurred to me several times that it might be something better than a comet. But I have been careful not to advance this supposition to the public.” -Giuseppe Piazzi

So it begins again: the neverending debate about who gets to be a planet and who doesn't. Everyone can bring their own interpretation of the science to the table -- and everyone has their own preferred naming scheme -- but when I think about the Solar System, I try to think about it in the context of all star systems.

Believe it or not, as far as we're able to tell, they all have some very important things in common.

Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration. Click for an incredible experience!

One is that -- in the grand scheme of things -- all star systems are intimately connected in the sense that no star, as far as we can tell, is ever born in true isolation. Large molecular cloud complexes eventually undergo gravitational collapse, forming large numbers of stars all at once, anywhere from hundreds to tens of millions of stars in a single cluster! Although the stars that form in these clusters will come in a wide variety of sizes and masses, they all have many similar properties, including the same rough proportion of heavy elements to one another.

But with the exception of the highest mass, globular star clusters, these large groupings of stars don't last very long.

Image credit: Fred Espenak of http://astropixels.com/, of the Hyades cluster.

The closest star cluster to us, the Hyades (just 151 light-years away), is in the process of dissociating, where repeated gravitational encounters with (or within) the disk of our galaxy drive the individual stars making a star cluster apart. Our Sun, itself, was very likely once a part of a similar cluster of thousands of stars, born some 4.5 billion years ago in one of our galaxy's ancient star-forming regions!

But when they do form, these stars aren't the only things that come about.

Image credit: C.R. O'Dell/Rice University; NASA.

What will eventually become each star, to the best of our knowledge, starts out as a triaxial ellipsoid, undergoes gravitational collapse, forming a star (or stars) near the central region, pancakes along the shortest axis, and winds up forming a protoplanetary disk around the central protostar. The entire complex rotates with some angular momentum, and the protoplanetary disk itself typically lasts for a few million years.

Image credit: NASA / FUSE / Lynette Cook.

During this time, there are a few physically interesting things fighting for superiority.

The young star (or stars) are shining brightly, emitting both intense radiation and charged particles, creating not just an inward gravitational force but also an outward flux of particles of both matter and radiation.
Small gravitational perturbations or instabilities in the disk are racing to grow as large as they can and accrue as much mass as they can before the disk boils away.
Denser objects -- as well as objects with larger mass-to-surface-area ratios -- are relatively less affected by the outward flux of the star(s), but are simultaneously subject to resistance (and mass accrual) from the particles they run into.

The net result of all this is that denser bodies and larger bodies tend to migrate inwards, and that the young star system begins to act as though there's a net buoyant force, pulling denser objects inwards and forcing the less dense objects to the new system's outskirts.

Image credit: Dr. Avi M. Mandell, NASA / Goddard Space Flight Center.

This might sound like an amazing, unique story, but -- at the end of the day -- it's all just straightforward physics, and these are the inevitable consequences of our physical laws. In addition to that, there's a tremendous temperature gradient around the star(s), where objects very close to the star (inside the Soot Line) have complex molecules (like polycyclic aromatic hydrocarbons, or PAHs) photodissociate, and objects beyond the Frost Line can condense into ices, but not inside.

Image credit: NASA / JPL-Caltech, InvaderXan of http://supernovacondensate.net/.

So, with that in mind, what is a typical star system -- once it's all grown up -- going to look like?

Inside the Frost Line, there can be rocky planets, gas giants, and moons, where the density of these worlds will tend to decrease as we move away from the central star. Beyond that, there will typically be a belt of frozen particles accrued at the Frost Line, exemplified by the asteroid belt in our own Solar System. (Sorry, Giuseppe Piazzi; it wasn't a planet, after all!) Outside of the Frost Line, it's typically only going to be puffy, gas giant worlds (although mini-Neptunes count) that can clear their orbits and exist as planets-as-we-know-them, and finally there will be both a scattered disk and a large, spheroidal cloud of frozen planetesimals, all of much lower density than the inner, rocky worlds.

Image credit: Karim A. Khaidarov, 2004, of http://bourabai.kz/solar-e.htm.

Measurements of the densities of worlds in our own Solar System confirm this picture, as do the first measurements of some exoplanetary systems.

So that's what pretty much every star system is going to look like: worlds interior to a system's frost line that can be a mix of rocky planets and gas giants, rock-and-ice asteroids at the frost line, gas giants exterior to the frost line, and mostly-ice-worlds beyond that in a scattered disk and in a spheroidal distribution beyond that.

Image credit: Oort Cloud image by Calvin J. Hamilton, inset image by NASA.

So what does that mean for considering an object a planet in our Solar System, or in our experience in general?

It means that there's a fundamental difference between the round worlds in hydrostatic equilibrium that have cleared their orbits interior to the frost line and all others, and it means there's a fundamental difference between the gas giant worlds beyond the frost line and all others, and it also means that all the frozen worlds -- both the ice-and-rock worlds at the frost line as well as the mostly ice worlds out beyond them -- are ubquitous and super common.

Image credit: NASA's The Space Place, via http://spaceplace.nasa.gov/ice-dwarf/.

If we make only the rocky worlds (and gas giant worlds) interior to the frost line planets, we have four planets. If we add in the gas giants beyond the frost line, we'd have four more, for a total of eight. If we decided to add in all the worlds in hydrostatic equilibrium -- or with enough gravity to pull themselves into a sphere -- we'd have something like an estimated 200 planets.

Mercury, Venus, Earth and Mars aren't special because they're spheres; they're special because of where they are and what their formation history is! They're special because of their densities, temperatures, atmospheres (or lack thereof, right Mercury?) and locations.

Image credit: Alien Robot Zombies by Bryan Magnum, at http://www.alienrobotzombies.com/.

If I had my way, that's what I'd teach everyone about the Solar System, and that's why I think that eight planets is just the right number for our Solar System. You may (and many of you, I'm sure, will) disagree, but this knowledge and understanding is part of the driving force behind Pluto's 2006 "demotion" from planetary status, not some vendetta against the cold, icy worlds of the Kuiper Belt, Oort Cloud and other locations beyond our Solar System's frost line.

Our eight planets are all special, and all the gas giants and rocky-worlds-interior-to-a-frost-line are special in exactly the same way. The asteroids, Kuiper Belt objects and Oort Cloud objects may be special in their own way as well, but it's a decidedly different way than these worlds that we presently call planets are. So remember that the next time you argue about what is-or-isn't a planet; this is how the Universe really works, and everything else is just a name!

esiegel Wed, 11/27/2013 - 12:03

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Er, no. They are not "special in exactly the same way". There's a difference between the group of rocky bodies and all others, sure. There's a difference between the group of gas giants and all others, sure. But the two groups themselves have nothing special in common. They do not cohere into a single exclusive group that excludes the other 200 planemos in our solar system . . . unless you deliberately and carefully pick a definition that has no purpose except to create a small list of "planets" that schoolchildren can memorize.

At which point, one might ask why we don't adopt similar rules for "galaxies", so that kids can memorize a nice convenient list of a half dozen to a dozen or so. Just because it wasn't traditional to have a short list of them dating back to the ancient Greeks?

"unless you deliberately and carefully pick a definition"

Well, that is the definition of defining. Making it up as you go along without thought is NOT how you define words.

And the 8 planets DO have something in common:

a) Hydrostatic equilibrium
b) Orbiting a Star
c) Not a star itself
d) Is the major player in its orbit. In other words, their orbit can be predicted solely on their sun's influence.

a) isn't true of asteroids
b) isn't true of rogue planets
c) isn't true of stars
d) isn't true of pluto, ceres, et al (to a list of maybe 200)

The ONLY ONE that you're disagreeing with is (d) and the ONLY reason to disagree with it is if you want Pluto to be included in a list of planets of our sun.

Because dropping (a) would make it tens of thousands of objects. If you're not worried about the length of the list, why include (a) in your definition? 100,000 names is no more immemmorable than 200+.

"The closest star cluster to us, the Hyades (just 151 light-years away)"

Wouldn't that belong to the Ursa Major Moving Group? 70-90ly away, variously.

The Ursa Major Moving Group has dispersed to the degree that many stars in all directions around the sun are believed to have originated there, even if a small core remains in Ursa Major.
If this group gets the status of a cluster, we would be living inside its boundaries. Try to explain that to school kids.

"Try to explain that to school kids."

That's absolutely no problem at all. They'd go "Cool!".

Their *parents* on the other hand are a bit reactionary...

"d) isn’t true of pluto, ceres, et al (to a list of maybe 200)"

As Neptune was discovered because of its influence on the orbit of Uranus it is demonstrably not true for Uranus either!

Yes, David, your cunning assholishness beat my scientific rigour.

".....beat my scientific rigour."

Ah, it's trying to hide over here is it. Why not try and drag it over to the pedal-power thread?

What? Feeling lonely, Dai?

So if a ring of asteroids forms at the frost line, what then happens to it as the star heats up over time? Are the volatiles slowly evaporated and pushed outwards?

Oh, and when will we come up with a good definition of continent?

Shouldn't planetary formation take into account, pre-stellar ignition, stellar ignition and post stellar ignition, conditions. Also the impact of heat radiated from the forming planet upon the surrounding dust cloud (heat generated from impact, compression and radioactive elements).
Upon ignition a massive cloud wave front is pushed out to the edge of the system driven by new solar winds and expanding gases, favouring lighter elements and giving already existing stony worlds a massive coat, the further out the greater ( a balance between diffusion of stellar energy input, volume of dust cloud and rapid growth of the gravity well).
Forming planets also within themselves start to create conditions where denser elements are more likely to accumulate and lighter elements are driven off, with the bulk of the accumulation of volatile and light elements being post ignition when the massive much denser waver front passes.
As well as catastrophic solar system formation (planets out of sequence) as being the norm, no matter how disturbing rather, rather than adjusting system formation models to suit.
So the question remains, how much planetary accumulation occurs prior to stellar ignition and how it changes after stellar ignition, with only first stage suns being fusion ignited and 2nd, 3rd stage suns being fission ignited (access to newly created radioactive elements), which also significantly alters planetary formation. So sun colour allows modelling of likely solar systems.

So this means the asteroid belt now exists where Sol's frost line was? What happens to the soot line?

Ethan Siegel, I love your work but afraid on this topic I have to respectfully disagree.

I think Pluto and the other ice dwarfs worlds count as planets as much as any other planets do and are all special in their own ways too.

All planets formed out of the swirling debris cloud from the largest to the smallest.

All planets, to me, are gravitationally rounded, not shining by core nuclear fusion and not moons of other planets. That's how I see it and how I think the term makes most sense.

As for the number of planets - if there are over 200 of them then (shrug) there are over 200 of them. Why is that bad?

We already know there are (almost certainly) more than millions of planets out there round other stars. Should our solar system settle for a mere eight because of our counting bias? I don't think so.

If Pluto was where Earth was we'd be in no doubt it was a planet.

If Earth orbited where Pluto was would we really quibble then? I doubt it.

What difference does a frost line really make when you have objects that are clearly one thing - round, fascinating, worlds in their own right -rather than any other - cometary nuclei, asteroids, etc .. ?

You have different objects forming of different substances at different distances sure, but why when one reaches the right level, right size, call it something else if its made of ice and rock versus just rock or mostly gas?

If a person is tiny and a crowd of similar small individual humans we don';t say s/he stops being a person do we?

A small animal, a small plant, found in a herd or a forest or grassland of suchlike living things isn't any different - they are still what they are - animal or vegetable not something else that they really aren't.

So it is too, in my view for planets, sure they may be small, sure they may be in a zone full of similar planets but planets they still are.

If you disagree, please explain,exactly why you think that should not be considered the case?

PS. A dwarf star is still a star - indeed almost every star is a dwarf star including our Sun.

A "dwarf" variety of almost every plant or animal species is counted as still belonging to that species in science, regardless of how numerous the individuals in its flock / pack / herd / forest / shrubland / reef, etc .. might be.

The scientific convention and precedent thus seems very clear and seems to say that dwarfs are still planets /animals / plants, etc ..

Dwarfism is not an excluding factor from being 'X' whatever 'X'may be!

Beyond the frost line is where worlds like Jupiter, Neptune and Pluto formed.

So, if we make that our divide then why count Jupiter and Neptune but not Pluto? Doesn't make sense to me.

If we shift to cleared orbits - again that's really problematic because no orbit is really that "clear" and if a rogue planet entered the solar system and entered a collision course with Earth or Venus would that stop either of them being planets? Surely not!

And what about a world that hypothetically forms right on the boundary - half outside the frostline and half within? Planet or not?

Also, if memory serves, we know that some comets formed at least partially close to the Sun from results from particles back from one of them (Wild 2 I think?) apparently formed in the inner solar system. So, could the same be true of Pluto and its kin? Could Pluto have formed at least partially in the inner solar system and migrated outwards? If so what does that do to the whole inside the frostline = planet; outside = not idea?

No, sorry Ethan, I just don't buy this line of argument here. We may just have to agree to disagree.

"Beyond the frost line is where worlds like Jupiter, Neptune and Pluto formed.

So, if we make that our divide then why count Jupiter and Neptune but not Pluto?"

It's explained in the ATL text, Steve.

Did you read it?

The frost line is not "the end of the planets", it's the end of the small rocky ones.

Because past that point, water, the most common molecule in a protoplanetary disk, can stop around for a bit and be picked up and, being far more common than silicon et al, that means a lot more mass.

"I think Pluto and the other ice dwarfs worlds count as planets as much as any other planets do"

And there's a bloke works down the chipshop, thinks he's Elvis.

"and are all special in their own ways too. "

Yeah, you didn't read ATL at all, did you, steve.

The asteroids, Kuiper Belt objects and Oort Cloud objects may be special in their own way as well, but it’s a decidedly different way than these worlds that we presently call planets are

"PS. A dwarf star is still a star – indeed almost every star is a dwarf star including our Sun."

Irrelevant.

In Tolkein, Dwarves are a different race. Here in real life, they're humans.

The words mean different things depending on where they're being used.

So "Dwarf Stars are stars!" is not proof dwarf planets are planets.

Indeed your continual whining about that point is why the IAU nearly didn't create the category "Dwarf Planet" because people whinging will use it to say the IAU are wrong. It's why they didn't do "Classical Planets". And it may be the few people who wanted pluto argued into being a planet like the others argued for its inclusion: so they can say to themselves "It's still REALLY a planet!".

Dwarf star being a star is irrelevant to whether a dwarf planet is a planet.

Why?

Because of the definition of star and planet. Dwarfism in stars still mean they fuse elements in their cores under self-ignition. Since that is the definition of a star, they're stars.

Dwarfism in planets mean they haven't cleared their orbit, which is a requirement for being a planet, so dwarf planets are not planets.

Dwarfism in planets mean they haven’t cleared their orbit, which is a requirement for being a planet, so dwarf planets are not planets.

So, according to that neither Jupiter nor Neptune are planets as they haven't cleared their orbits!?

As for dwarf planets being planets, they fulfill the IAU criteria bar the clearing the orbit part. So to say they aren't a sub-type of planets seems a stretch. If they manage to clear the orbit, excepting trojans, do they then magically become real planets even if they stay out beyond the Kuiper belt?

Ethans explanation makes sense to me the IAU not so much.

"So, according to that neither Jupiter nor Neptune are planets as they haven’t cleared their orbits!?"

No, according to that definition, both Jupiter and Nepture are planets because they've cleared their orbits.

As for dwarf planets not being planets, they do not fulfill the IAU criteria in all cases. So to say they are a subtype of planets is wrong. If they managed to clear their orbits, then they will become planets, just like the protoplanetary disk becomes a planet when it coalesces into one and stops being a planet when it's broken into many pieces that do not have the size to retain hydrostatic equilibrium.

Ethan's explanation is untroubling to the IAU.

The only trouble are whiners who don't want pluto to be ousted from planet status because, well, who the hell knows...

Ceres is a planet, and our solar system does not have only 8 planets, at least according to the equally legitimate geophysical planet definition. 19th century astronomers did not know that Ceres is in hydrostatic equilibrium and therefore a complex world that doesn't belong in the category of asteroids and comets. It makes little sense to lump objects that structurally and compositionally are much more akin to the larger planets than to asteroids and comets with the latter category. It also makes little sense to require an object to "clear its orbit" to be a planet. We cannot look only at where an item is; we have to look at the individual item and what it is. These small spherical worlds are planets that have most of the same features the rocky planets have; the only difference is they are smaller.

The notion that we have to limit the number of planets in the solar system because we cannot have too many makes absolutely no sense. Memorization is not important to learning. Kids can be taught the different subclasses of planets and the characteristic of each subclass. After all, we don't require kids to memorize the names of all rivers or mountains on Earth or the names of all Jupiter's 67 moons.

The "IAU criteria" are not some gospel truth that should be taken as THE standard an object has to meet to be considered a planet. They represent one point of view in an ongoing debate. And they could result in the same object being considered a planet in one location and not a planet in another, something that makes absolutely no sense.

Why not instead recognize that some planets clear their orbits and some don't? Similarly, some planets have no orbits to clear as they don't orbit any stars (rogue planets). Yet structurally, they are planets.

Exoplanet systems clearly show that our solar system is not necessarily typical in its formation or layout. Every time an anomalous system is discovered, astronomers are sent back to the drawing board in determining how that system formed. There may very well be more than one way to make planetary systems. Otherwise, how do you explain hot Jupiters in close orbits around their stars? How do you classify giant planets in extremely elliptical orbits that travel through asteroid belts in those orbits? How do you determine what it means for an orbit to be "clear?"

Dwarf planets are special in the same way the larger planets are and are NOT special in the way asteroids, comets, and Small Solar System bodies are. The latter are frequently loose rubble piles shaped only by their chemical bonds. They are tiny and don't have the complex structure that dwarf planets, which are small planets, have.

This isn't about Pluto. It is about a dynamical versus a geophysical definition of planet and about whether the term planet should be kept narrow or broad. Given that Dawn has shown Vesta, which is not completely in hydrostatic equilibrium, to be more planet-like than asteroid-like, why not wait for the data from New Horizons and Dawn to show us just how unique and complex Pluto and Ceres are?

Watch your language, methane.

There is no Frost Line. Such a line is cute, but rather arbitrary and capricious, not to mention unscientific in the extreme. Someone's had too much pumpkin pie!

There are other troubles besides Pluto huggers, methane. One, for example, are name-calling, pompous trolls who kowtow to the IAU.

To bring up estimates is a red herring. There's only a handful of dwarf planets. Making them a subclass of planets is endorsed by over 200 distinguished planetary scientists. Maybe even Frosty the Snowman, as well, who lives on the right side of your beloved Frost Line. Estimates are for realtors, not those making scientific definitions. Get a grip.

Mike, to bring up the number is a red herring: that isn't your complaint.

Pluto is not a planet.

Telling others "get a grip"when you've been throwing a hell of a tantrum about pluto not being a planet is rich.

"There is no Frost Line"

WOW!

So according to mike the shitheaded little moronic retard, water DOES NOT FREEZE.

Shitting pope on a rope, you're a moron!

"Ceres is a planet, and our solar system does not have only 8 planets, at least according to the equally legitimate geophysical planet definition"

Ceres is not a planet, and our solar system has 8 planets discovered so far.

The geophysical definition was posited by mike the childish arsehole and he never managed to actually define it and backtracked off any definition claimed several times.

That geophysical definition

a) is not known by you
b) has not been tested as to whether it meets your claims by you
c) is not the valid definition of a planet.

Pluto is not a planet.

Get over it.

"Ceres is in hydrostatic equilibrium "

So is Titan.

So therefore by geophysical definition, it's a planet.

Oh, no, it's not, is it.

ALL you know about the geophysical definition is

a) the words
b) the idea that it claims pluto as a planet

and those, frankly, are the only things you care about.

Accuracy and rigour is something alien to you morons.

There you go again, methane.

Don't put words on my mouth, troll.

Yes, water freezes. There's ice on Mercury, Earth, and Mars, genius. The Frost Line isn't in the current IAU definition. Therefore, you shouldn't support cutting off planets on its colder side, lackey that you are, correct?

Yeah, all that facts and reality and all that jazz. I keep going with it, but you repeat your whine.

Pluto is not a planet. Get over it.

"Don’t put words on my mouth, troll.

Yes, water freezes. "

Then there IS a Frost Line.

I never put words in your mouth: I only showed you how moronic your statement "There is no such thing as a Frost Line" is.

Then you got all butt hurt.

Just like you did when you came up with a "definition" of the geophysical definition of a planet THAT WASN'T THE DEFINITION. Then you went "I never said that was all it was".

Well, you never said that it was incomplete either.

But here you go again, "not saying" the stupid things pointed out as the MEANING of your asinine and vapid whinier outpourings.

Pluto is not a planet.

If you wanna talk about the geo def, talk to the person who just defined it, genius.

The Frost Line is a silly concept by some blogger. It is not anything of note, in my opinion. Nor is the Soot Line. Soot is what comes out of your mouth during your vile rants and vulgar profanity-laced ravings.

Don't waste my time. Try being intelligent or shut up.

Pluto is not a planet.

Repeated because you seem incapable of grasping this fact.

"The Frost Line is a silly concept by some blogger."

http://en.wikipedia.org/wiki/Frost_line_%28astrophysics%29

Yup, you're a moron.

Whatever, methane.

To use the Front Line to keep Pluto and Ceres from being replanetized is a pathetic, desperation move. Knowing full well that the current IAU definition is short-lived due to it holes and the nefarious way in which it was passed on St. Bartholomew's Massacre Day 2006, now Pluto's problems are not only that it is "too small" but also that it is "too cold."

Pathetic.

Mike Brown, as you know, when he first co-discovered Eris told he wife that it was a planet. Then, when he realized the IAU wasn't going to call it a planet, he quickly changed his tune and went after Pluto in another desperation move.

When I correct you, I do not call you a moron. I expect the same courtesy, methane. Why don't you grow up and stop idolizing grown men who behead dolls?

I mean, "Frost Line," of course.....

Dwarf planets are planets. Dwarf stars are stars. Dwarf galaxies are galaxies. Get over it, methane. Be consistent. Be a sane, logical person who does not resort to incessant insults and name-calling. Otherwise, go away. You are not contributing anything productive here until such time as you heed my advice.

"I mean, “Frost Line,” of course….."

What? That thing in astrophysics that you thought was made up by Ethan on the spur of the moment for this post???

Dwarf planets are not planets.

Not even you believe that bullshit, otherwise you wouldn't be whining about the IAU definition that makes Pluto a dwarf planet.

Pluto is not a planet.

moron mike: "Whatever"

Yeah, like you being wrong is a "whatever".

Actually, for once you're right: this indeed is the reason why your whines are irrelevant to the definition of planet. Because your opinion and "knowledge" on the subject is irrelevant and a "whatever".

You wish, methane.

No, it is, mikey.

Why are you here? Go collect some frost or something. The adults want to talk now, methane.

No, according to that definition, both Jupiter and Nepture are planets because they’ve cleared their orbits.

Both Jupiter and Neptune have their own sets of Trojan asteroids in their orbits. Their orbits are, therefoere, not cleared.. Just saying they have cleared their orbits doesn't make it so, however much you may wish it to be true.

If they managed to clear their orbits, then they will become planets

So dwarf planets can become planets by changing one minor condition. Feel free to consider them not planets but you are stretching a minor thing into a major issue.

Even before it had almost completely cleared its orbit most people would have called Jupiter a planet not a dwarf planet.

Why are *you* here, mike?

Pluto isn't a planet.

If you want to change that, then get out there and organise to get the definition changed.

"Both Jupiter and Neptune have their own sets of Trojan asteroids in their orbits"

Yup.

But those are moons and asteroids of zero impact on Jupiter's orbit.

Jupiter owns its orbit. It dominates it.

Pluto does not.

Pluto is not a planet.

Jupiter is.

"So dwarf planets can become planets by changing one minor condition."

Yes.

Just like an SSB can become a planet by changing two.

Or a planet can become an SSB if it breaks up.

Where is this problem you seem to be alluding to?

Maybe I am, methane. I can multi-task.

Earth doesn't clear its orbit, either. We share our orbit with, at last count, 19,500 other celestial objects. Great defintion, methane. Don't dominate this comment board, bro.

"Clearing the orbit" does not mean there are no other objects in the orbit: it means that the body is large enough, with enough of a gravitational field, so that if other bodies are in the orbit they are deflected or pulled in: either way, they do not exert noticeable influence on the larger object's path. Those other objects do not influence Earth's movement: not so with the smaller bodies.

Remember, dean, mike knows fuck all, but is DAMN certain that the IAU are wrong, so anything is believed to that end.

Hell, the moronic arsehole kept bleating on about the "geophysical definition" then came up with a definition that WASN'T geophysical. When called up on it, changed the definition completely with the Jedi hand-wave of "That was not a complete[ly accurate?] definition".

But if it wasn't complete, why wasn't it in the second attempt at defining it?

Because the moron hasn't a fucking clue.

"Maybe I am, methane."

Am what?

Wrong?

Hell yes.

"I can multi-task."

Gosh? Really? So what?

"Earth doesn’t clear its orbit"

The earth has cleared its orbit.

Moons, asteroids, dust clouds, comets, LGMs, santa clause and photons et al don't count.

Pluto hasn't: Neptune is none of those.

There should be, by definition, 9 classical planets. These are the objects in hydrostatic equilibrium discovered in the period before we had telecopes in orbit. When you talk of true planets, there are 8, with ~200 dwarf planets or planetoids. Yes, this is all semantics, but science is full of these. Why is Greenland not a continent? Why are Europe and Asia different continents? Why is a tomato a vegetable that has no business being in a fruit salad? What about an avocado? Don't even get me started on true nuts vs. culinary nuts. Think peanuts, pecans, walnuts and cashews all belong in a single can marked "mixed nuts"? We use simple inaccurate classifications all the time. Leave the simple 9 planets alone. Call them classical and go wild with meaningful classifications for those who dig deeper. To me, that is part of the beauty of science. Like a wise ogre once said, it is like an onion.

Get off my back, troll.

Ethan is simply reiterating the dynamical definition of planet, which centers on where an object is. That is why he argues that objects beyond the Frost Line cannot be considered planets. I disagree because as a supporter of the geophysical planet definition, I cannot support a classification system that completely ignores what an object is and categorizes it solely by where it is. Not everything beyond the frost line is a tiny planetesimal. Some objects in the outer solar system are much larger and far more complex. Pluto has an atmosphere, and its density is closer to that of the rocky planets than to that of tiny KBOs. Ethan also repeats the argument that having "too many planets" somehow makes the term less "special." I disagree with this as well. Does the fact that there are billions of stars in the galaxy and billions of galaxies in the universe diminish the words "star" and "galaxy?" I don't think so.

The further a planet is from its parent star, the larger an orbit it will have to "clear." That is an inherent bias of the dynamical planet definition. We know from exoplanet systems that not all solar systems form the same way and that there are many different patterns of planetary migration, many of which we do not yet fully understand.

Any classification that puts Jupiter and Earth in the same category but excludes objects like Pluto makes no sense. Earth has more in common with Pluto than with Jupiter. Both Earth and Pluto are rocky worlds rounded by their own gravity. Both have large moons formed via giant impacts. Both have nitrogen in their atmospheres, and both are geologically differentiated into core, mantle, and crust. In contrast, Jupiter's composition is far more like that of the Sun, largely hydrogen and helium. It has no solid surface and has its own "mini-solar system" of moons and rings.

The geophysical planet definition is this: A planet is a non-self-luminous spheroidal body orbiting a star or free-floating in interstellar space (the latter referring to rogue planets).

There is no single legitimate definition of a planet. Wow, your constant repetition of the same statements does not make them anything more than one side in an ongoing debate. Science is not decided by a decree from a person or group who call themselves an "authority." You should know that.

It's not my job to define terms for you. Someone just defined it a few posts ago. I'm not your servant, methane.

"There should be, by definition, 9 classical planets."

The term classical planets was overwhelmingly voted down, Tim.

"These are the objects in hydrostatic equilibrium discovered in the period before we had telecopes in orbit."

This "definition" is *exactly* why "classical planets" was quashed, Tim.

And it would make for 5 planets, not nine.

"Why is Greenland not a continent? Why are Europe and Asia different continents? "

Geographers don't have a definition of continent.

But that has naff all to do with the IAU, astronomy, or the definition of planet.

The mantra that there are probably 200 dwarf planets in our solar system is a red herring, a rhetorical device to cloud the issue. There is only a handful of known dwarf planets. Don't drink the Kool-Aid.

"That is why he argues that objects beyond the Frost Line cannot be considered planets."

Ah, so when you talked about what Ethan was saying, you'd never actually READ what he said.

"I disagree"

Ditto.

But your disagreement with the definition is worthless.

Sorry.

That's just the way it is.

Pluto is not a planet.

They geophysical definition, never mind mikey's ridiculous non-definition of it, doesn't work.

The current definition does.

Pluto is not a planet.

"It’s not my job to define terms"

Indeed it isn't.

Yet you still whine and bitch that your definition isn't taken when EVEN YOU don't know what it is.

"But your disagreement with the definition is worthless.
Sorry.
That’s just the way it is.
Pluto is not a planet.
They geophysical definition, never mind mikey’s ridiculous non-definition of it, doesn’t work.
The current definition does.
Pluto is not a planet."

Your statements above are not science. They are an attempt to impose your view and only yours onto an ongoing debate. My disagreement is worthless--why? Because you say so? The fact that you write statements like this says more about your shortcomings in defending your position. The geophysical planet definition works just fine; that view is held by many scientists, not just by me and Mike W. Trying to "lay down the law" like a dictator does nothing to support your case. Please address the issues I raised regarding the problems inherent in the dynamical definition.

According to the geophysical planet definition, Titan, Ceres, and Pluto are all planets because they are celestial bodies in hydrostatic equilibrium orbiting a star.

"The further a planet is from its parent star, the larger an orbit it will have to “clear.” That is an inherent bias of the dynamical planet definition."

And is a problem WHY? It's not even why pluto doesn't get to be a planet.

There's more orbit, but less stuff. And the stuff out there is generally bigger because they can take on ice as a constituent.

That, too, is an "inherent bias".

But then you've not said why it's a problem, have you?

"Any classification that puts Jupiter and Earth in the same category but excludes objects like Pluto makes no sense."

Nope, it makes perfect sense.

That is why the definition was nearly unanimously passed by people whose job it is to deal with these things as scientists.

"Earth has more in common with Pluto than with Jupiter."

First, nope.

Second, "having something in common with Earth more than it does with Jupiter" would be a stupid definition of planet. So it isn't part of the definition.

Again, a non problem.

"Both Earth and Pluto are rocky worlds"

Do you know what Pluto is?

ASTEROIDS are rocky.

That doesn't make them planets.

"Both have large moons formed via giant impacts"

Ah, that answers my question: no, you don't know anything about pluto.

Charon wasn't formed like our moon was and Pluto didn't gain it the same way. And adding the masses of both together still fall short of the moon's mass.

"Jupiter’s composition is far more like that of the Sun, largely hydrogen and helium."

And you don't know either Jupiter or the Sun, either.

Well done.

"The geophysical planet definition is this: A planet is a non-self-luminous spheroidal body orbiting a star or free-floating in interstellar space (the latter referring to rogue planets)."

Then the Moon is a planet?

EVERY asteroid is a planet?

EVERY comet a planet?

The entire Oort cloud a planet?

You'd have uncounted, nay, UNCOUNTABLE numbers of "planets".

And SOHO would be a planet by your definition there too.

That isn't the geophysical definition of a planet.

But I guess you'll not let ignorance get in the way of a moronic opinion, will you?

"According to the geophysical planet definition, Titan, Ceres, and Pluto are all planets "

And that's why the geophysical definition was not used.
PS why didn't Luna become a planet? It's a damn sight bigger than Pluto.

"Your statements above are not science"

They're facts.

"There is only a handful of known dwarf planets."

cf your earlier laughable attempts at stating "fact" that turned out to be a turd sandwich of ideas, mikey.

You are wrong.

As usual.

"My disagreement is worthless–why? Because you say so? "

No, because you are a clueless idiot with strong opinions on something you know nothing about.

Pluto:
Ice surface.
Ice layers beneath.
Rock and iron core. Not molten.
Atmosphere: freezes out.

Earth:
Rocky surface.
Molten layers beneath.
Molten iron sub-core
Solid iron core.
Atmosphere: persistent.

Yeah, they have soooo much in common...

Jupiter: Rocky core maybe 20 earth masses.

Pluto: Rocky core, maybe 1/450th an earth mass.

The loudest voice should not get to win the arguement.
1) Who voted down the term classical planet? How was it "overwhemingly"?
2) I was not aware we had telescopes in orbit before the discovery and original classification of Pluto as a planet. Please list the name of the orbiting observatory that leads to your list of five plants.
3) You missed my larger point that all scientific classification is inherently messy. I purposely made an analogy to other fields of science. If you dismiss an analogy because it does not meet a specific definition (i.e. having to do with the IAU) you have missed the point of using an analogy.

If your facts are so strong why do you have to berate people in order to make your points? Please try to keep your replies to my above questions respectful or don't bother to answer.

"The loudest voice should not get to win the arguement."

Yeah, so stop screaming, Tim.

What DID win the argument was the discussion over 10 days the definition of planet that the IAU then voted on that states that there are only 8 planets and that Pluto is not one of them.

But you and a few other stridulent hawkers of ignorance keep bleating as loud as you can to change it.

The loudest voice should not win the argument.

"If your facts are so strong why do you have to berate people in order to make your points? "

I don't.

The points, however, are never listened to by you morons so I need to club them into your thick skulls with the bluntest tools available.

Even then, the work never seems to stick.

I was not aware that I was screaming. And you ignored all of my questions and jumped right into insulting me. You could have answered with facts, but you chose personal attacks. I am not sure what 10 day debate you are referring to, but the Great Planet Debate at Johns Hopkins in 2008 left no concensous.

If you don't have to berate people to make your points, ask yourself why you chose in that very post to call me a moron and not answer my questions? Science advances with the debate of ideas, not personal insults. It is in my opinion a shame you berated your way into dominating this discussion. Have fun talking to yourself. I am done.

"I was not aware that I was screaming."

Ah, but you thought I was loud.

How does that work?

I answered some of questions of yours, Tim.

And many more have no purpose to being answered since they do not progress any understanding at all.

And several have been rhetorical.

And a few asinine.

And I note, Tim, that despite all the wailing you make, you've not yet noticed that your definition of classical planets make 5 planets, not 9.

What is your problem with me saying there is only a handful of known dwarf planets?

You just want to disagree with everything for the sake of being disagreeable? It is working. Are you going to repeat the mantra about the 200 dwarf planets supposedly lurking beyond our ken? There could also be 865 Jupiters, too. Speculation of this kind is a cheap rhetorical device. Why stoop to that? Don't you want to be taken seriously?

"What is your problem with me saying there is only a handful of known dwarf planets?"

I have no problem with it.

Your problem with it is that it's wrong.

Entirely wrong.

Ripsnortingly wrong.

If you'd any sense of self worth or dignity, embarrassingly wrong.

But you won't let reality impinge upon your "right" to make shit up to support your flatulent cause.

You are full of it.

Why is it wrong?

Because the figure is known to be 45 and there are maybe 150 other known candidates for the same categorisation, dumbass.

Because you apparently think the "200" is made up when that is only your ignorance and arrogance speaking.

Because it's wrong.

There are a shitload more than a handful of dwarf planets.

I am full. However, what's your problem with that?

"That is why the definition was nearly unanimously passed by people whose job it is to deal with these things as scientists."

Really? The majority of the 424 IAU members who voted on the planet definition are NOT planetary scientists but other types of astronomers. Planetary scientists are the people who most deal with planets, and they, not cosmologists or specialists in one of the many other areas of astronomy, are the ones whose job it is to define the term planet.

The reason I noted that Earth has more in common with Pluto than with Jupiter is to show the weakness of the IAU definition, which puts Earth and Jupiter in the same category but excludes Pluto.

"ASTEROIDS are rocky. That doesn’t make them planets."

Asteroids are rubble piles loosely held together and shaped by their chemical bonds. In contrast, planets are shaped by their own gravity, which squeezes them into a round shape. Asteroids are not geologically layered and are not complex worlds with geology and weather the way small planets are. How is blurring the distinction between tiny, shapeless asteroids and complex worlds good science?

Yes, according to the geophysical planet definition, the Moon is a secondary or satellite planet. I don't understand why this is a problem for you. If an object is massive enough to be squeezed into a round or near-round shape by its own gravity, it is a small planet. If it tiny and too small to be rounded by its own gravity, it is an asteroid or comet. SOHO is not a celestial body but an artificial satellite, which is why it is not a planet.

Pluto is estimated to be 70 percent rock. We don't know much about its core, but that will change with the New Horizons flyby. Pluto's atmosphere never completely freezes out to the point of being lost. Scientists now believe Pluto maintains at least some of its atmosphere throughout its 248-year orbit.

"Charon wasn’t formed like our moon was and Pluto didn’t gain it the same way."

Charon is believed by scientists to have formed when a proto-planet smashed into proto-Pluto early in the solar system's history, much the same way as Earth's moon formed when a Mars-sized object impacted the Earth.

"Jupiter: Rocky core maybe 20 earth masses."
At this point, that is speculation. It is still unclear whether Jupiter even has a solid core.

"What DID win the argument was the discussion over 10 days the definition of planet that the IAU then voted on that states that there are only 8 planets and that Pluto is not one of them."

First, this is a scientific debate, and unlike political debates, it is not about winning and losing. Nothing "won" because debates are constantly reshaped as new and better information becomes available. Four percent of the IAU voted on the 2006 resolution, which was hastily thrown together in the last 24 hours of the General Assembly. An equal number of professional astronomers signed a formal petition rejecting that definition. Seven years later, many astronomers continue to reject it. It was never even close to being approved "unanimously." Ninety-six percent of IAU members couldn't vote because they weren't in the room on a particular day, and no electronic or absentee voting was allowed. And immediately after the vote, one man who did vote asked for Pluto to be put back on the list of planets. Watch the video, and you will see this. He was told by Jocelyn Bell Burnell that it was too late; the resolution had already been adopted. This means he wasn't clear about the resolution he had just voted for!

The list of planets was actually in the footnotes of the resolution, and if you watch the video from the beginning, you will see that there was a lot of confusion over whether the footnotes did or did not count as part of the resolution.

"Ah, that answers my question: no, you don’t know anything about pluto."
I know Pluto is NOT an asteroid.
Is that what you say to everyone who disagrees with you?

45 in your delusions, methane. And why do you keep using the figure of 200?

Shall I name the known dwarf planets to you like Santa's reindeer?

Ceres, Pluto, Charon, Haumea, Makemake, and Eris. You could also list the moons as satellite dwarf planets like Luna and Triton, Ganymede, et cetera. It does not come close to 45. What comic book did you find that figure in?

Do you know what the word "known" means? Maybe that is your current problem.

@16. Wow :

“Beyond the frost line is where worlds like Jupiter, Neptune and Pluto formed. So, if we make that our divide then why count Jupiter and Neptune but not Pluto?” -StevoR

It’s explained in the ATL text, Steve. Did you read it?

Yes I did indeed. Doesn't mean I necessarily agree with what I read though.

"The frost line is not “the end of the planets”, it’s the end of the small rocky ones. Because past that point, water, the most common molecule in a protoplanetary disk, can stop around for a bit and be picked up and, being far more common than silicon et al, that means a lot more mass."

Yes.

And?

The way planets form is fascinating - but it is NOT definitive.

Why the blazes should it be?

Is a person no longer a person if they were born by IVF or caesarian section versus "natural" birth?*

is a plant not a plant if it grows from cuttings instead of seed?

Course not!

Why then should a planet be a non--planet just because it formed beyond a certain distance?

Answer : It shouldn't.

Besides how do we know or sure that Mars or even Earth and Venus didn't start forming beyond the frostline and subsequently migrate inwards?

*Well, okay, it worked for MacDuff in the Scottish play and Eowyn in the 'Lord of the Rings' but that's another two stories entirely! Besides Eowyn and MacDuff are definitely still classed as human / people / animals too.

@86. Mike Wrathell : "Do you (Wow) know what the word “known” means? Maybe that is your current problem."

I would guess that "Wow" has a lot of problems - her / his trolling here being just one of them.

Did Wow eventually ever actually answer my questions on the other 'Triton Kuiper King' thread or elsewhere btw? Must go take a look I 'spose.

Oh & Wow for the record - the number of currently known dwarf planets larger than Pluto is zero. Eris is about the same size and just a smidgin more massive. Makemake, Haumea, Sedna and others are smaller and the number of ice dwarfs currently known is from my memory much closer to fifty than two hundred. Not that it really matters anyhow.

Note : there are thousands of confirmed Jupiter mass & gas giant planets in the Milky Way and beyond. That sure doesn't stop them being classified as planets. So then why should knowing about however many more ice dwarf planets make them any less planets either?

Hint : Trick question - it shouldn't. There are thousands of exo-Jupiters and maybe hundreds of intra-Plutos and all of them are still properly considered planets given a reasonable (i.e. not the IAU's!) definition of the word.

@45. Chris' Wills : Yes. Exactly. Seconded. Hundred percent.

@62. Wow : "Yet you still whine and bitch that your definition isn’t taken when EVEN YOU don’t know what it is.

Among others, I have already suggested what my preferred definition of planet is and it is far superior to the IAU's ridiculous one.

Again, a planet in my view is gravitationally rounded, so not an asteroid or comet nucleus, not self-luminous by nuclear fusion hence not a star and not directly orbiting another planet so not a moon - three straightforward, decisive tests.

I've also noted that other alternative definitions exist that would also count Pluto as a planet such as Ken Croswell's here :

http://kencroswell.com/NinthRockFromTheSun.html

(Read that link yet, Wow? No? Refusing to look at evidence and arguments disagreeing with yours still Troll?)

So, that falsifies that rude and erroneous assertion of yours right there, Wow.

@51. dean :

"“Clearing the orbit” does not mean there are no other objects in the orbit: it means that the body is large enough, with enough of a gravitational field, so that if other bodies are in the orbit they are deflected or pulled in: either way, they do not exert noticeable influence on the larger object’s path. Those other objects do not influence Earth’s movement: not so with the smaller bodies."

Actually those bodies *do* influence earth's orbit just relatively slightly. hence gravitational boosts. Yes the extent of the gravitational influence (perturbation) depends on a few other factors such as closeness of approach and velocity of the encounter but still there certainly is an effect.

So where do you draw the line? Who decides it and what if objects and cases that are right on that line?

Oh & where did you get that idea from that "clear" is exactly what you said as opposed to other ideas of what it means?

The fact that the IAU definition raises the needless superfluous* question of what "clear" actually even means is a major point against it given the key scientific principle of Occam's razor.

* Yes I know that is a tautology. It is also deliberate emphasis.

Really? The majority of the 424 IAU members who voted on the planet definition are NOT planetary scientists but other types of astronomers.

And since the planetary scientist is working on the earth, not alien planets, meanwhile those planets are astronomical objects, and moreover this is an astronomical definition not a geographical one, the IAU members were field experts to judge.

Meanwhile you don't even know about the planets you're wibbling on about other than their names. See #64.

The reason I noted that Earth has more in common with Pluto than with Jupiter is to show the weakness of the IAU definition

Except as shown in #69, that statement is wrong and you only bring it up to "support" your complaint, but that statement, being false, does not support your complaint being valid.

Asteroids are rubble piles loosely held together and shaped by their chemical bonds.

Asteroids are rocky bodies. According to what you claim to be the geophysical definition of a planet, that counts as a planet. NOTHING about "rubble piles".

Oh, and the chemical bonds do not hold the piles of rubble together. It seems like you don't know even the basic science and refuse to let your ignorance impede your insistence.

Charon is believed by scientists to have formed when a proto-planet smashed into proto-Pluto early in the solar system’s history

No, Charon was assumed to be caught like Pluto was into a resonant circuit with Neptune as a kuiper belt object.

First, this is a scientific debate>/blockquote>

Not the way you do it. You have to have actual scientific knowledge and you don't care for that: you make up sciencey claims and don't really sweat actually knowing what the science is. See above.

debates are constantly reshaped as new and better information becomes available

Which is why the geophysical definition of a planet was abandoned: the better information showed that the definition was not capable of the job of defining planet status.

That's why it took 10 days to come to the state where there was a proposal to vote on.

Four percent of the IAU voted on the 2006 resolution

100% were invited to. Not voting means that you don't really have anything to say and defer to those who do. So yet another non-problem.

Ninety-six percent of IAU members couldn’t vote because they weren’t in the room on a particular day

If they'd wanted to vote, they could. They didn't. And therefore didn't stay. Yet more non-problem.

one man who did vote asked for Pluto to be put back on the list of planets

Yup, unanimity isn't required in ANY democratic process. Another non-problem.

He was told by Jocelyn Bell Burnell that it was too late; the resolution had already been adopted

Yup. And when the "wrong pary" wins an election you have to either get enough votes to get a new election or wait until the next election to change it. You don't get as a single person to whine and demand that the voters got the wrong answer and they have to do it again. Well you do, but you deserve being told "too late".

Yet another non problem.

“Ah, that answers my question: no, you don’t know anything about pluto.”
I know Pluto is NOT an asteroid.

Ah, I see. You can't read either.

And why do you keep using the figure of 200?

Because it's the right one.

Pluto is estimated to be 70 percent rock

Nope.

It's estimated to be 50-70% rock by mass.

By volume, it's mostly (50-80%) ice.

"Do you know what the word “known” means?"

Yes.

Shall I name the known dwarf planets to you like Santa’s reindeer?

Ceres, Pluto, Charon, Haumea, Makemake, and Eris

Uh, that's only 6.

There are 45 known.

Another about 200 known candidates who may turn out to be dwarf, most of which *will* be dwarf.

Yes I did indeed. Doesn’t mean I necessarily agree with what I read though.

But disagreeing with it doesn't mean you can pretend it never said what it said, Steve. Yet you pretend it says other than it does and whine about this "strawman" post.

Disagreeing with it doesn't mean you get to make up what it says.

Is a person no longer a person if they were born by IVF or caesarian section versus “natural” birth?*

They aren't planets. No matter how they're born.

is a plant not a plant if it grows from cuttings instead of seed?"

They aren't planets, no matter how they're germinated.

Why then should a planet be a non–planet just because it formed beyond a certain distance?

That isn't in the definition of a planet. See above for how you don't get to make up a strawman merely because you disagree with what was said.

Note : there are thousands of confirmed Jupiter mass & gas giant planets in the Milky Way and beyond.

NOTE: The English alphabet has 26 letters.

"I would guess that “Wow” has a lot of problems – her / his trolling here being just one of them. "

Nope, I have a lot of idiots to combat, but that's barely a problem.

PS the definition of troll isn't "Won't let me win an argument".

"@45. Chris’ Wills : Yes. Exactly. Seconded. Hundred percent."

Oh indeedy, they do have trojans.

However, that doesn't mean they aren't planets.

So if that was the bit you were 100% agreeing with, then you're 100% wrong.

"the number of currently known dwarf planets larger than Pluto is zero"

WRONG.

6 is a handful. Perhaps there are 39 possible candidates, but only 6 are dwarf planets as of this day. Sedna is not a dwarf planet. We don't have enough data on it. Maybe Putin can send you there to report back on it.

Eris is smaller than Pluto. Therefore, Pluto is the largest known dwarf planet. Sicardy said so.

methane, if you aren't a troll, why do you live under a bridge?

"6 is a handful."

Indeed it is.

45 is not.

"Eris is smaller than Pluto."

Proof required, pls.

mike, if you're not an ignorant twat, why do you post like one?

This discussion is getting heated, but what's it all about anyway.

If there's one thing clearly shown is image no.8 (mass/density graph) is that there is no real way of distinguishing between objects in Sun's orbit. It isn't about size or mass or orbit only, it's just terminology. If Europa i.e. was in it's own orbit between Mars and Jupiter, it would be classified as a planet. Since it's not, it's Jupiter's moon. If Pluto was i.e. the size of Earth or bigger, regardless how far it was, it would still be a planet in classification. Doesn't really have to do with science per say.. it's our own conventions. That simple.

I do agree however with those who think that the whole classification system should be perhaps a bit more scientific. It is a somewhat arbitrary at the moment IMO. But at the end of the day it's just classification, people. You are arguing about if the line should have been drawn 2 cm lower, without any real reason.

Is same as arguing if one species of flowers should be categorized under rose family or tulip family... irrelevant really, as long as it's there for everyone to see and admire :)

"I do agree however with those who think that the whole classification system should be perhaps a bit more scientific"

It is scientific.

What is non scientific about it?

The definition is based on measureable features of the bodies that do not rely on earthican-biased presumptions and also are observable characteristics of the body that can be measured and tested.

It IS scientific.

I agree that non-planethood has NO BEARING *WHATSOEVER* on whether Pluto is a worthy body in the solar system for scientific and astronomic review.

See Bruno Sicardy's paper on the occultation of Eris. What's it like to live under a bridge?

Sinisa

Nice sentiment, but injustice is injustice.

"See Bruno Sicardy’s paper on the occultation of Eris."

See Pons and Fleischmann's paper on Cold Fusion.

"but injustice is injustice."

BWAHAHAHAHAHAHAHAHAHAHA!

Why?

Why not?

@ Wow

I didn't say it's not scientific. I said IMO should be MORE scientific as is now IMO a bit arbitrary.
At the moment we chose between 4, 8 or 200, depending on what to include/exclude in the definition. We chose 8. I would also choose 8 over 200. Like I said.. it's classification. And all is good until one day we'll find solar systems with perhaps 40-50 bodies in our definition of planet. And then we'll change the definition again probably to keep to some managable number. Will our definition be based on science... of course. But still it has a lot to do with us ourselves. So it's 50% social as well as 50% science.

@ Mike

sorry but I see no justice or injustice in all of this. Justice is a human notion, and since no human has been affected or harmed by this, what is the injustice? If someone i.e. owned a piece of land on Pluto and by demoting it to dwarf status lowered the land value, then you would have something to argue about. I can understand your sentimental attachment to Pluto... but that has nothing to do with justice or law or moral values.

"I didn’t say it’s not scientific. I said IMO should be MORE scientific"

So I need a wetter glass of water to drink?

Sorry, unless you're claiming the definition isn't scientific, you're going to have to explain what "MORE scientific" means.

"At the moment we chose between 4, 8 or 200, depending on what to include/exclude in the definition."

Nope.

We choose the current definition because that keeps the definition useful to us.

We chose not to use a different definition because that definition would include so many objects in our own system that the definition becomes useless.

The current definition is the most scientific one.

"We chose 8. I would also choose 8 over 200. Like I said.. it’s classification"

And the choice WAS NOT "Lets have 8". It was "What definition works to keep the number of planets found by the definition useful".

If we'd chosen "Lets make it these 8" then that would be unscientific and tautological to boot.

THAT WAS NOT THE DEFINITION.

If Pluto had not been waay out there beyond the frost line, it would likely have been lighter than Ceres.

@ Wow
more scientific in order to give a precise answer to a following question:
- if an object of Mercury size was found beyond Neptune with cleared orbit, would it be classified as a planet? I think it would. That's our current definition. It is based on our solar system. What about if it's was 0.98 size of Mercury.. or 0.995.. where do you draw a line? In other words we use the sizes of our own planets. When we discover more and more of smaller planets in other solar systems, I'm pretty sure the definition will change. But not because science changed or some universal things. We changed. Thus, like I said before, it's 50% social.

You yourself wrote: "We chose not to use a different definition because that definition would include so many objects in our own system that the definition becomes useless."... And I agree with this 100%. Just this is not science.. this is social. And there is nothing wrong with it. That is what I meant by arbitrary. If we as a society were a bit dumber we would choose the definition that gives only 4. If our brains were more of a chess type, we would love the definition that has 200 items. I don't consider that 100% scientific.

"- if an object of Mercury size was found beyond Neptune with cleared orbit, would it be classified as a planet? I think it would."

Yes, it would.

"It is based on our solar system"

Only because you've questioned about a planet in our solar system. That's the only place you find Neptune. I.e. you're wrong because you're creating a tautological strawman.

If a planet the size of mercury were found around Barnard's Star more than 27AU from that star and had cleared its orbit, it would also be a planet by the definition.

AND NONE OF THAT IS BASED ON OUR SOLAR SYSTEM.

" What about if it’s was 0.98 size of Mercury.. or 0.995.. where do you draw a line?"

Where it is not massive enough to attain a near-spherical shape.

Which YET AGAIN has fuck all to do with our solar system and is ONLY about the physical characteristics of the body in question.

"You yourself wrote: “We chose not to use a different definition because that definition would include so many objects in our own system that the definition becomes useless.”… And I agree with this 100%. Just this is not science.."

WRONG.

IT IS SCIENCE.

Science is the useful description of the reality we see around us, which is why, for example, "supernatural" claims or other claims that are inherently untestable are not scientific: they can produce no useful conclusion.

"In other words we use the sizes of our own planets"

Yeah, you're a moron.

Look, if you don't like that PERFECTLY DESERVED label, here's a tip: learn what the fuck you're talking about BEFORE you type that crap out, M'kay?

In other words: your claim is aberrantly and monstrously wrong.

If Pluto, or any of those other dwarf planets, had been in an orbit cleared of any other major influencing body, THEY WOULD BE PLANETS.

If the earth, despite being much bigger than pluto, were in the EXACT SAME ORBIT, not merely "beyond Neptune", then the earth would be a dwarf planet.

Before complaining about the arbitrary nature of the definition, LEARN THE FRIGGING DEFINITION.

jeez man.. take a pill.. you'll get a heart attack

Nope, your fake concern is noted and discarded for the passive aggressive bullshit it is.

How about, instead of fake concern for a strawman attribution of me to attack, you decide to actually take some time to inform yourself BEFORE you spout yet more uninformed "opinion" on this thread?

After all, this should be a learning experience for you, and I want you to learn as much as you can.

Sinisa

The way in which Pluto was demoted by the IAU by ramrodding was very unjust and political. It had nothing to do with science. The definition was designed with the specific intent to demote Pluto and the by-laws of the IAU were not followed so that only lackeys of the the Executive Committee's cabal to demote Pluto were aware of what was going to go down. The few rational people who realized Pluto is and always will be a planet were grossly outnumbered as a result of this injustice.

Of course, to convince methane (Wow) of this would be like trying to convince him that living under a bridge is not the best abode for a human being. But, what the Hell, he likes living under a bridge, troll that he is, and who am I to judge?

methane

you have called me every name in the book, can't take the heat, huh? no wonder you live under a bridge.....those cool winds, huh? maybe i should try it sometime.....

"The way in which Pluto was demoted by the IAU by ramrodding was very unjust"

No ramrodding happened, mikey.

You lost. That's all.

" can’t take the heat, huh"

It's a comfortable 20C.

What is your source that says there are 45 known dwarf planets? Superman? Krypton is not in our solar system, methane, and it blew up a long time ago.

"Mike Wrathell
December 3, 2013

methane"

Irony:

"you have called me every name in the book, can’t take the heat, huh?"

"What is your source that says there are 45 known dwarf planets?"

Astronomers.

They are unpublished amateurs?

They are not recognized. It's just an urban myth.

Lost only due to ramrodding. The vote was a joke. You just choose to deny the facts.

"They are unpublished amateurs?"

No.

"Lost only due to ramrodding."

No, lost due to being wrong.

Let me know when the IAU confirms them. Urban legends don't count. Nameless myths.

Ah, so you believe the IAU when it comes to what's a Dwarf Planet, but not when it comes to what's a Dwarf Planet...

How does that work, mikey?

PS When the IAU say that Pluto is bigger than Eris, get back to me on which is the biggest.

Not much choice there, methane.

Never heard of Bruno Sicardy?

No disrespect to amateur astronomers. The point being these 39 or so so-called dwarf planets out there have not been confirmed by the IAU which is the only international body that names things and confirms discoveries. So to speak of them as if they are a done deal is premature. Furthermore, to throw out the 200 figure is even more premature. It seems like a red herring, but, at best, it is speculation of some sort, based on what, probability? Is that what planetary science has come to?

I can do probability, too. I think it is probable, that you, methane, will be flying off the handle in the next 48 hours and making a troll of yourself once again.

But, maybe not. Probability is not my forte.

Boo! Hiss!

Until you want to start insisting that dwarf humans aren't actually humans, I think you should admit that dwarf planets are planets.

What we need are better categories, like
(1) Terrestrial Planets: Mercury, Venus, Earth & Mars
(2) Gas Giants: Jupiter & Saturn
(3) Ice Giants: Uranus & Neptune
(4) Hadean Planets: Pluto, etc.

That's a lot more informative than making the silly claim a hydrostatically stable body orbiting the sun is not a planet.

There's no point in arguing this issue- you're arguing arbitrary definitions.

There can even be confusion and argument as to what constitutes a star- If it's massive enough to fuse Hydrogen into Helium, there's no question, but what about brown dwarfs that can fuse lithium only?

Let them be stars, too. Otherwise, they might get a complex.

You said it, Jan!

Since many scientists go by " Size does Matter " than Titan should be called a planet.

I love how distracted human beings are that distraction divorces them from what they actually are. Even the ugliest things have an intricate aspect of beauty and grandeur, however, and although distraction disgusts me, it turns out beautiful. (I would knock a psychiatrist cold with that punch. Ha, ha, ha.) This is coming from a non-human being, by the way, which is what I am. Every intelligence that is looking at this situation IS the situation. DUH! One IS the thing(s) one is looking at, perceiving and interacting with, the same as one is the perceiver/actor. The words of the article speak of elemental energies forming form itself, and I laugh constantly that human intelligence generally posits that primate intelligence is the only possibility in the vastness of space that harbors a superior form of intelligence. Read my lips: superior intelligence is everywhere and in all things. It's Omnipresent. Just because one may not be intelligent enough to perceive particular kinds of intelligence "out there," does not mean that intelligence is not "out there." Kapish? Thus, quit being so distracted that you don't know who/what you are. It entertains me too much! I laugh involuntarily. And that distracts me! You may have an infectious disease, and giving it to me, which threatens to turn me into the same thing(s) you are. But hell, on second thought, do whatever you will, and I will simply respond if it hits me just right. If not, I'll remain disappeared and nobody will know I'm here. Chances are, most of my responses will be mirthful, though, because I think your condition is comedic, even though it may seem as much as life-threatening to you-all. I am laughing at you. Ha, ha, ha. This is not cruelty. My laughter is moved 100% by nature, and nature is not cruel. Part of why I laugh at human gesticulations/foibles is because of the posturing that creates such widely divergent contrasts between fantasy and reality that it just cracks me up. Nothing is more vital than I am, for instance, yet virtually everything I come across says that there is plenty more vital than I. What said things are doing is denying their own existence and it has nothing to do with me. There is no way I can deny my existence. It's as close to me as the nose on my face. Yes, I have a nose on my face. Doesn't everything? Ha, ha, ha. If not, I just have it become that way, only for me, because I like me. Even more, I love me. So, all you humans as would like to dot so, go ahead and deny your existence, and I'll simply continue affirming mine until what, hell freezes over? Ha, ha, ha.

Earth was a captured COMET along with the other inner rocky planets. As " high-falutin" as this presentation looks and sounds, it's not necessarily correct. After all, animated charts and slick illustrations don't prove anything. Even I could pay someone to make a cartoon where Bluetoe kicks Popeye's ass and mops the street with his head, no matter how many cans of spinach he eats.

Ole Velikovsky was right about many things. Yes, he made some errors too, but who hasn't? Even the iconic Jew, Einstein, made a few boners along his way.

"We chose 8."

No, WE didn't choose 8. The astronomers of the world didn't choose 8. A total of 333 of the 424 people in a room in Prague, who had already violated their own bylaws by bringing a last minute resolution before the General Assembly without first vetting it by the appropriate committee chose 8. And an equal number of professional astronomers signed a petition rejecting that choice. Most IAU members cannot afford to attend the whole conference or even part of the conference. Those that left early were misled into believing a different resolution, the one put forward by the IAU's own committee, would be voted on. Dr. Owen Gingerich, who headed that committee, said in retrospect that had he known the General Assembly would vote on a different resolution thrown together at the last minute, he would have changed his plans to leave early. He didn't know because this last minute change was an act of subterfuge by a tiny group that wanted to get their way.

What kind of scientific organization does not allow electronic voting? These astronomers write complex computer models; certainly one of them could create a secure electronic voting method so that those who couldn't attend the General Assembly could still vote.

It isn't 4, 8, or 200 planets. At the moment, it's four (terrestrials) plus four (jovians) plus more (dwarf planets). The number of dwarf planets, like the number of exoplanets, is likely to remain in flux for a long time as new objects are discovered.

It is an injustice to mislead people into believing that a politically-motivated decision constitutes science. It is also an injustice to the general public to present only one side of an ongoing debate as fact when this is not the case.

All I got right now to add is that I am going with the solid count on dwarf planets. As they are confirmed by the IAU, my count will go up one at a time. There "may" be 200. There "may" be 300 or 400 or 433 in our solar system. But, a dwarf planet in the hand is worth two in the Oort Cloud or the Scattered Disk.

Pluto, the ninth planet, in name.

"All I got right now to add is that I am going with the solid count on dwarf planets"

Except that isn't the solid count of Dwarf Planets. That is the list of named dwarf planets. The IAU has a comittee to name them.

Pluto is a Dwarf Planet by the same people you are insisting are the sole authoritative source on what is a Dwarf Planet.

"No, WE didn’t choose 8."

Right, for entirely the wrong reasons, dear.

"Earth was a captured COMET"

No it wasn't.

"Since many scientists go by ” Size does Matter ” than Titan should be called a planet"

No.

1) "many" isn't shown to be a valid reason for this assertion
2) "many" isn't shown as being true in itself
3) Titan is a moon, not a planet

The Geophysical definition WOULD make Titan a planet.

It would make our moon a planet.

They are not.

So the definition cannot be the Geophysical one.

The definition is the one given by the IAU.

"There’s no point in arguing this issue- you’re arguing arbitrary definitions."

Actually, Mike and the other morons aren't arguing even that.

They don't even know the definition they propose, only that it keeps pluto as a planet.

"Until you want to start insisting that dwarf humans aren’t actually humans"

Why?

Planets aren't human.

"The point being these 39 or so so-called dwarf planets out there have not been confirmed by the IAU which is the only international body that names things and confirms discoveries."

NOT BEEN NAMED by the IAU.

And they define Pluto as a Dwarf planet and NOT a planet.

"There’s no point in arguing this issue- you’re arguing arbitrary definitions."

By the way, ALL definitions are, definitionally, arbitrary.

If it were not, there would be only one language.

Jan,

Protoplanetary disks are the pre-formed planet. Are we to call them "planet babies"?

The spilling of toxic chemicals and abuse of the planetary resources is abuse of planets, so should that be considered similar to child abuse?

We don't pay the planet for the work it does. Is that slavery?

Or are all those ridiculous, because planets aren't humans?

I know the geo def, methane. The unnamed dwarfs are also unconfirmed. Why are you such a cantankerous asshat?

"I know the geo def"

No you don't you moronic piece of shit.

You can go the other room now, you worthless dipshit. No one wants you here. You are a smelly, cantankerous cretin.

Sorry, was this your blog, dear?

See ya!

Bye!

When they originally made Pluto not-a-planet, the rationale was that its orbit intrudes on that of the next planet in, which seems good enough to me, but doesn't provide an opportunity to augment the C.V. like this article did.

No one said the IAU has to confirm the unnamed dwarf planets for them to be considered dwarf planets. What is needed, at least according to the geophysical planet definition, is sufficient observation to determine that these worlds are in hydrostatic equilibrium. In some cases, such as that of Sedna, there is uncertainty because the objects are so far away. If there is conclusive evidence an object is in hydrostatic equilibrium, then it is a dwarf planet, regardless of what the IAU says or doesn't say.

On several occasions, I have observed elementary school teachers adopting the term "baby planets" to refer to the dwarf planets. Why not?

We do in fact enslave and abuse the Earth via pollution and a factory model that insists on ever-increasing yields with no rest period. That isn't how the Earth works, and it risks depleting our soil and turning fertile areas into deserts. This has happened before. Humanity's current interaction with this planet is extremely dysfunctional and leading towards a mass extinction and a harsher climate for most of the planet.

Technically, you are right, of course, Laurel. But I do not want Pluto, or any other dwarf planet to have an asterisk after it. Oh, we have 8 planets, and then there is Pluto*.

In a perfect world, the IAU would do its job and there would be no need for you to mention a possible need for a new international astronomical body.

Anyway, how many dwarf planets are there besides the 6 the IAU has confirmed in your estimation? Wow, aka "methane," says there are 39 or so more. I did not think Sedna was a dwarf planet. I think the same problems Sedna has would also plague the other candidates, otherwise, the IAU would have confirmed them.

"What have we done to the Earth? What have we done to our fair sister?"

~~~~~Jim Morisson of The Doors

"What have they done to the earth?
What have they done to our fair sister?
Ravaged and plundered and ripped her and bit her
Stuck her with knives in the side of the dawn
And tied her with fences and dragged her down...."

"When The Music's Over" by The Doors

http://www.youtube.com/watch?v=jSMAWh6vnXo

"No one said the IAU has to confirm the unnamed dwarf planets for them to be considered dwarf planets. "

You mean nobody but mikey here.

Or are you calling him nobody?

2But I do not want Pluto, or any other dwarf planet to have an asterisk after it. Oh, we have 8 planets, and then there is Pluto*."

So make it

We have 8 planets.

That is truth. And no asterisk.

PS I thought you were buggering off. Again.

"On several occasions, I have observed elementary school teachers adopting the term “baby planets” to refer to the dwarf planets. Why not?"

Because people will then complain about child abuse when we send probes to impact on these babies.

And I was talking about the protoplanetary disk, not the dwarfs.

Bloody hell Wow, bro, you still trolling this thread and topic?

@95. Wow (3rd December , 2013) :

"Yes I did indeed. Doesn’t mean I necessarily agree with what I read though."-StevoR

But disagreeing with it doesn’t mean you can pretend it never said what it said, Steve. Yet you pretend it says other than it does and whine about this “strawman” post.

Wrong as usual Wow. I'm well aware of what Ethan wrote, I just don't agree with it for thee reasons I've already explained.

"Disagreeing with it doesn’t mean you get to make up what it says."

Funny coming from you given that's all you ever seem to do.

Also again complete misrepresentation of what I've said as I've come to expect from you bro.

" I’m well aware of what Ethan wrote"

Oh, OK, you're ignoring what Ethan wrote and making up a strawman to attack, then.

Is this better or worse?

"Funny coming from you given that’s all you ever seem to do. "

Yeah, a citation on that would be handy, dear.

Irony:

#176 StevoR
December 5, 2013

Bloody hell Wow, bro, you still trolling this thread and topic?

@106. Sinisa Lazarek :

"Is same as arguing if one species of flowers should be categorized under rose family or tulip family… irrelevant really, as long as it’s there for everyone to see and admire :) "

Except we're at a level much more basic than the equivalent of the species /genus divide. This is more like arguing whether roses are animal mineral or vegetable!

Clearly they're vegetable just as Pluto is clearly a planet not a star or asteroid! Saying otherwise is just, silly, really.

@99. Wow :

“the number of currently known dwarf planets larger than Pluto is zero”
WRONG.

Shouting in all caps doesn't make you right y'know, Wow - it is you who is wrong in your unsupported deliberately provocatively rude assertions as per usual.

Eris is about the same size as Pluto in radius, slightly but not very much more massive.

So yeah, the number is zero or maybe just one depending on how you define "larger".

Certainly there is no other ice dwarf that is significantly larger than Pluto in both size and mass yet discovered. After a long period of searching we haven't even added any extra ones the same size as Pluto suggesting objects its size are still relatively rare.

@132. Wow :

“What is your source that says there are 45 known dwarf planets?”
Astronomers.

Really? Which astronomers exactly? Citation very much needed.

@142. Jan Vones :

"Until you want to start insisting that dwarf humans aren’t actually humans, I think you should admit that dwarf planets are planets.

What we need are better categories, like
(1) Terrestrial Planets: Mercury, Venus, Earth & Mars
(2) Gas Giants: Jupiter & Saturn
(3) Ice Giants: Uranus & Neptune
(4) Hadean Planets: Pluto, etc.

That’s a lot more informative than making the silly claim a hydrostatically stable body orbiting the sun is not a planet."

Exactly!

Informally, we already have divisions amongst planets both in our solar system and beyond based on their size, orbits and compositions.

The IAU definition, incidentally, in a further example of its idiocy and uselessness rules out planets beyond our solar system altogether - a ruling that is, of course, appropriately ignored by almost everyone when talking about planets outside our systems showing just how wrong the IAU definition actually is.

To be scientifically useful a definition needs to be applied to new and unknown cases and help work out what object X gets classified as. Starting with must orbit only our star out of the billions around shows a pathetic lack of imagination and sets up a ridiculously narrow limit.

For broad categories such as planets (or animal or plant or mineral categories) a definition really needs to be much more inclusive than the opposite.

@ 158. Wow :

“Until you want to start insisting that dwarf humans aren’t actually humans”
Why? Planets aren’t human

I'm beginning to wonder if you are human, frankly, Wow.

To miss the point by such a colossal margin and fail to grasp what is meant by an analogy almost suggests you're some kind of spambot rather than just a particularly willfully obtuse or contrary troll.

No planets aren't people -but dwrafs of class X are all still consistently included in categories of object X. Being a small example of something doens't mean that something isn't something.

But then you really know that very well and are just posting here to irritate the rest of the people here aren't you, Wow?

@178. Wow : people can actually scroll up this thread and see what you and I and others have posted Wow. That's your citation.

Or maybe just one of them.

"“the number of currently known dwarf planets larger than Pluto is zero”
WRONG.

Shouting in all caps doesn’t make you right y’know"

However, typing in caps makes the word easier to read.

And being right is what makes me right in this case, you know.

Eris is about the same size as Pluto in radius, slightly but not very much more massive.

Neither of which was the claim that I said was WRONG. So irrelevant. Making a statement never made as if it were some form of referral to a previous statement is called lying, steve.

It's naughty. Stop.

What is your source that says there are 45 known dwarf planets?”
Astronomers.

Really? Which astronomers exactly?

Just fucking google it, moron.

http://en.wikipedia.org/wiki/List_of_possible_dwarf_planets

Informally, we already have divisions amongst planets both in our solar system and beyond based on their size, orbits and compositions.

Formally, we have planets. 8 of them. And many Dwarf Planets of which Pluto is one.

Apparently, this is not allowed to stand, however.

"EXACTLY!".

To be scientifically useful a definition needs to be applied to new and unknown cases and help work out what object X gets classified as.

Which is why the geophysical defition fell down. Why the definition the IAU gives was accepted by those able to test whether the definition met those criteria.

But you refuse to accept those criteria unless it lets Pluto be a planet.

"EXACTLY!"

To miss the point by such a colossal margin

There was no point. Only rhetorical shiboleths of the whiney bunch.

Dwarf planets are not planets.

Dwarfism in humans is not a case of a human not clearing its orbit.

End of.

-but dwrafs of class X are all still consistently included in categories of object X.

Not dwarf planets.

The definition of dwarf does not require your assertion. You will be 100% incapable of accepting this, despite absolutely no ability to locate a citation proving otherwise.

Why?

Because you're a moron.

@168. Americanegro :

"When they originally made Pluto not-a-planet, the rationale was that its orbit intrudes on that of the next planet in, which seems good enough to me, but doesn’t provide an opportunity to augment the C.V. like this article did."

Actually it was known almost from the start that Pluto's orbit crossed that of Neptunes leading to speculation for a while that Pluto was in fact an escaped moon of Neptunes. This oddity was not considered cause for removing Pluto's status at the time.

Nor is planets having crossing orbits considered valid cause for removing them from the planets category now because for example we know of at least one exoplanetary system, HD 45364 b & c where two gas giant worlds have a similar situation to the that of Neptune and Pluto and both worlds are acknowledged as planets -see :

http://kencroswell.com/HD45364.html

The main "reason" people seem to have for removing Pluto's planetary status seems to be because there are a number of similar worlds nearby that are almost or in the case of Eris pretty much exactly as big as Pluto.

Funnily enough, we don't consider this cause for removing the planetary status of gas giants or rock dwarfs like Jupiter and Earth from planetary status when they too have similar worlds in their respective "zones" of our solar system. Although admittedly there are only three other examples of each as opposed to ten - perhaps fifty or more such worlds for the ice dwarf class of planet.

But still. It seems a matter of degree and principle here.

Having similar worlds nearby whether on crossing orbits or not shouldn't define when something is a planet any more than having similar animals of the same species nearby makes an individual animal not an animal.

This for "Wow"s benefit is an analogy NOT a claim that planets are animals. I'll spell it out for the troll here :

We don't say Earth isn't a planet even though it has Venus in a very close - especially as seen from the outer solar system - orbit nearby and these worlds have almost identical properties in many respects. (Eg. mass and diameter.)

We don't say Neptune isn't a planet even though it has Uranus in a similar orbit nearby and these worlds have almost identical properties in many respects. ( Indeed Neptune is physically smaller but more massive than Uranus so the question of which of those is"bigger" depends on what is meant!)

Therefore being consistent we have also surely got to say that we can't say Pluto isn't a planet even though it has Eris nearby and these worlds have almost identical properties in many respects. (eg. mass and diameter.)

IOW, having similar worlds nearby doesn't stop a planet from being a planet which seems to be the main "argument" for removing Pluto's planetary status.

The only difference is that there are more similar worlds like Pluto than there are like Earth and Neptune but this is not,I think, good or sufficient cause for reclassification because its just a degree in number not a fundamental property or definitional problem. It doesn't really matter because for example if we had ten Earths nearby we may describe our space as being crowded with earth-like planets but we'd hardly say they were all therefore asteroids instead!

"Actually it was known almost from the start that Pluto’s orbit crossed that of Neptunes leading to speculation for a while that Pluto was in fact an escaped moon of Neptunes. This oddity was not considered cause for removing Pluto’s status at the time."

It was thought that Pluto was much more massive, and it was the great mass of the presumed pluto that made it a "Planet".

Moreover, the larger asteroids were likewise not known to have a co-habiting cloud of other similar bodies, later called the asteroid belt. However, on finding one, that became the reason to change the (currently 23) planets back to 8. Nobody complained.

But Pluto, being found smaller than expected by a large factor and then finding it exists with many other similar bodies, such a collection being called the Kuiper Belt has meant that the astronomers, as they did with the Asteroids, created a classification of non-planet for the previously presumed planet Pluto.

And Lo, did the ignoranti shout!

"We don’t say Neptune isn’t a planet even though it has Uranus in a similar orbit nearby and these worlds have almost identical properties in many respects"

Indeed not.

Because both are dominants in their orbit, having cleared their orbit as per definition of planet, unlike Eris, Sedna, Pluto, et al.

"IOW, having similar worlds nearby doesn’t stop a planet from being a planet which seems to be the main “argument” for removing Pluto’s planetary status."

I guess if you make up what you see, you can see what you like.

Those of us constrained to humdrum reality have to merely look on at the lunacy of you and yours with wonderment and perplexity.

@ 183. Wow : Your source is wikipedia? LOL.

Gee, that's authoritative -Not.

"Neither of which was the claim that I said was WRONG. So irrelevant. Making a statement never made as if it were some form of referral to a previous statement is called lying, steve. It’s naughty. Stop."

Your claim was and I quoted you directly : “the number of currently known dwarf planets larger than Pluto is zero - wrong.”

The error - the wrongness here - was yours because Eris and Pluto are the same size (diameter) to within the error bars. It is true as I and others have said - with that supporting evidence - that there aren't any dwarf planets larger than Pluto - the number is zero. So, no lie on my part Wow, just an explanation and elaboration showing why your trollishly capitalised and unsupported claim of "wrong" was itself wrong.

"Formally, we have planets. 8 of them. And many Dwarf Planets of which Pluto is one. Apparently, this is not allowed to stand, however."

It isn't allowed to stand because there are very good reasons why your above asserted but unsupported claim of only 8 planets is wrong and why dwarfs planets logically must count as planets as much as giant and other ones.

"Which is why the geophysical defition fell down. Why the definition the IAU gives was accepted by those able to test whether the definition met those criteria."

Er, really? No. My point was the IAU definition excluded the main source of such new cases to which we have to ask the question - planets found outside our solar system . So no the IAU definition isn't good at all there and falls down completely on that point. Exoplanets are also planets no less than those in our solar system. A definition that excludes them isn't scientifically useful when the field of exoplanets is now one at the cutting edge of astronomy!

But you refuse to accept those criteria unless it lets Pluto be a planet."

I'd also reject any definition of animal that say a dog isn't an animal and any definition of a plant that says a rose isn't a plant - because any such definitions would clearly be ludicrously flawed.

"To miss the point by such a colossal margin .." [-StevoR]
There was no point. Only rhetorical shiboleths of the whiney bunch.Dwarf planets are not planets. Dwarfism in humans is not a case of a human not clearing its orbit. End of." -Wow

And here, yet again, you deliberately miss (or pretend to miss) the point completely, Wow. Because you are a troll.

No its not rhetoric, its logic.

Its also nomenclatural consistency which is important for understanding and teaching science.

Something that is a dwarf or small member of category X remains a member of category X - it isn't excluded from that category simply on the basis of its size.

This applies to animals, plants and everything else -including planets.

That's not merely my assertion that's how the field and its terminology works. We don't exclude dwarf stars from counting as stars, we don't exclude dwarf plants from counting as plants, so excluding dwarf planets from counting as planets would be and is illogical, inconsistent and wrong.

What part of this do you fail to comprehend (or will you pretend to fail to comprehend for trollings sake) exactly Wow?

D'oh. Messed up the italics there, sorry. Fixed version (hopefully!) here :

“To miss the point by such a colossal margin ..” [-StevoR]
There was no point. Only rhetorical shiboleths of the whiney bunch.Dwarf planets are not planets. Dwarfism in humans is not a case of a human not clearing its orbit. End of.” -Wow

And here, yet again, you deliberately miss (or pretend to miss) the point completely, Wow. Because you are a troll.

No its not rhetoric, its logic.

Its also nomenclatural consistency which is important for understanding and teaching science.

Something that is a dwarf or small member of category X remains a member of category X – it isn’t excluded from that category simply on the basis of its size.

This applies to animals, plants and everything else -including planets.

That’s not merely my assertion that’s how the field and its terminology works. Hence we don’t exclude dwarf stars from counting as stars, we don’t exclude dwarf plants from counting as plants, so excluding dwarf planets from counting as planets would be and is illogical, inconsistent and wrong.

What part of this do you fail to comprehend (or will you pretend to fail to comprehend for the sake of trolling to annoy others here) exactly Wow?

@ 183. Wow : Your source is wikipedia? LOL.

Which cites the original sources.

Oh, I get it: you're redefining what you want to ensure you aren't getting it!

Oh, you should have said! I wouldn't have wasted my time trying to give a moron what he never wanted in the first place!

The error – the wrongness here – was yours because Eris and Pluto are the same size (diameter) to within the error bars

Nope, the wrongness is the statement that Pluto is bigger than Eris.

Not in me pointing it out.

It isn’t allowed to stand because there are very good reasons why your above asserted but unsupported claim of only 8 planets is wrong

You keep claiming it's wrong, but you have nothing to substantiate that, only your "seemings" that you create out of your own psychopathy.

Er, really? No. My point was the IAU definition excluded the main source of such new cases to which we have to ask the question – planets found outside our solar system

Nope, the definition doesn't do that at all.

Please show where it does.

Specifically.

Something that is a dwarf or small member of category X remains a member of category X –

Not part of any definition of dwarf available in this universe, dear.

The IAU says there are 5 known dwarf planets.

No, they don't say that, mikey.

It's on their site, methane.

So it is, at least here:

http://www.iau.org/public/themes/pluto/

Q: How many dwarf planets are there?
A: Currently there are five objects accepted as dwarf planets. Ceres, Pluto, Eris, Makemake and Haumea.

Perhaps he has a link to another page that contradicts that.

Not likely, David.

I agree, that was written tongue in cheek. And even if he had, I'll give you any odds you like that he won't even entertain the notion that producing it only constitutes a draw.

Thanks, Wow, i learned so much from your comments here, about planets and cosmos and that there are so many people who wont try to understand, just wont think what they are, minds clouded, shouting. Thank you!

"It’s on their site"

No it isn't.

"Perhaps he has a link to another page that contradicts that."

Indeed I do, Dai.

Odd that, innit?

"Q: How many dwarf planets are there?
A: Currently there are five objects accepted as dwarf planets."

Not saying there are only. Key words:

Currently accepted.

But look beyond the mine you want so hard to be all there is:

Q: Are there additional dwarf planet candidates currently being considered?
A: Yes. Some of the largest asteroids may be candidates for dwarf planet status and some additional dwarf planet candidates beyond Neptune will soon be considered.

Q: When will additional new dwarf planets likely be announced?
A: Probably within the next few years.

Q: How many more new dwarf planets are there likely to be?
A: There may be dozens or perhaps even more than a hundred waiting to be discovered.

Hmm.

Seems like the IAU say there are perhaps more than a hundred out there. And indeed the wiki link that Steve petulantly refused to read indicates that there are indeed many MANY more than a hundred.

Odd how you did not link to support your claim, which is not only because it destroys your "argument" that there are only a handful of dwarfs, but also because it shows that your attribution was false.

Even more amusing is Dai wibbling on with how you're right, mikey, but didn't actually appear to read it at all before arriving at the conclusion he so desperately loves to prove.

Odd that, innit?

Not at all. It seems entirely in character Bu thanks, your own words illustrate your problem far better than mine ever will.

"Not at all. "

Yeah, I was being sarcastic.

I have no surprise that you're running a hypocritical stance, dear.

Learn how to read, methane. I said known, not candidates. Why are you such s peevish imp?

Learn how to read, methane. I said known, not candidates. Why are you such a peevish, pedantic imp? Had I given the link, you would've bitched about that. Grow up and admit when you are wrong.

" I said known, not candidates"

Not good enough Mike. You should have said "confirmed" or "named", anything the unambiguously defined your position. Wow has asked you a question similar to "What was the largest island in the world before Australia was discovered, and you have given the moronic answer "Greenland". He would rather argue semantically to prove himself "right" than let the argument move on to ground where he exposes himself to the risk of being wrong, or even worse, exposing the gaps in his understanding.

There are more known that currently accepted.

And that is known.

But odd.

Mikey, IAU count Pluto as a Dwarf Planet.

Have you now decided that they are right??!?!?

They aren't accepted until confirmed, thereby becoming known.

Pluto's slight is another issue from this.

They aren't nonexitent or unknown until they are confirmed, mikey. They just have to be recorded to be known to exist.

Your claims about what was said was a mine and reformation of their statement to server your ideology.

A mendacious lie, in other words.

Dai:

"Not good enough Mike. You should have said “confirmed” or “named”, anything the unambiguously defined your position"

You mean like I said earlier, post 153.

Seems like you have selective reading capacity if it serves your childish needs.

What's your problem? Learn English before you post again, methane. There are five known dwarf planets. Deal with it, genius.

Where's your problem: learn how to read, moron.

There are more than five known dwarf plants.

No, there's only five known dwarf planets, genius. Take it up with your beloved IAU when you hone your reading comprehension skills, whenever that might be.

No, there are more than 5 known dwarf planets, you fucking moron.

But, hey, maybe you can explain why a body so similar to Pluto in every way:

http://en.wikipedia.org/wiki/90482_Orcus

isn't a dwarf planet, you vapid and noisy retard?

Is it because it's too small? Well, Pluto is very close to the same size.

Is it because it has a companion nearly as big? Well, so does Pluto.

If you're trying to say that Orcus isn't a dwarf planet, what do you call it?

Because whatever you want to call it, you have to explain why Pluto isn't the exact same thing.

Orcus is not a dwarf planet according to the IAU. You are delusional.

Make your juvenile and petulant demands to the IAU. I'm not at your beck and call.

ROFL!!!

*MY* juvenile demands?

You will insist on the IAU being right on dwarf planets but not right on pluto being a dwarf planet.

The reason being that you want pluto to be a planet.

Orcus will be a dwarf planet if and when the IAU deems it deserves to be. Since it is nearing aphelion, it will probably be a while. Don't hold your breath, methane.

Someone besides Mike Brown needs to confirm things, methane. The IAU is the main group. Unfortunately, sometimes they let the worst part of human nature affect their actions, but they still are the body that names and confirms, so I don't have a lot of choice. I just wish they would do their fucking job without the bullshit.

Orcus is a dwarf planet, or not, whether the IAU meeting labels it or not.

"Someone besides Mike Brown needs to confirm things"

Already been done, mikey.

What? Ignorant again? You? With YOUR reputation?!?!?

Damn straight:

It was discovered on February 17, 2004 by Michael Brown of Caltech, Chad Trujillo of the Gemini Observatory, and David Rabinowitz of Yale University. Precovery images as early as November 8, 1951 were later identified

Aaaaaw.

PS, odd that you now defer to a decision by a selected committee on what constitutes a dwarf planet, planet, SSB and so on. I bet you won't be consistent in your assertions, though, will you.

poow widdw mikey....

I meant the IAU. Orcus sounds like it might someday be confirmed, but since it is so far away, probably not enough data for the IAU's liking. Whatever, it is not my field, nor my problem.

There is plenty of data on Pluto and more will be coming in, too, in the not-so-distant future.

Don't you have anything better to do than give me shit?

What about the IAU?

Pluto existed before it was observed. We didn't have to wait until the IAU named it for it to exist.

Really, you appear to have no idea at all but are flailing to avoid answering the question, mikey:

http://en.wikipedia.org/wiki/90482_Orcus

Why isn't it a dwarf planet?

The IAU have already given the definition. Where in that definition does Orcus not fit?

Come on, you've already shown you don't know what the geophysical definition of a planet is, lets see if you know what the IAU definition is.

Or are you scared?

It's not my department.

How in the fuck am I supposed to determine if fucking Orcus is rounded by its own fucking gravity? Fuck Orcus.

So you don't know what the geophysical definition of a planet is, but still insist it's as good as the IAU one. You don't know the IAU definition of a planet, but think it wrong.

And despite not being your department when you're asked to give your "reasoning" behind your claims, you're still going to make those claims, aren't you mikey-poo?

Why?

Because the DK is strong in you and you're never going to let a piffling fact get in the way of your opinions, uninformed though they are.

I know both definitions, dorkus.

No, you don't.

You claim it.

But you don't.

Whatever you say, troll.

David L., here is my response to the IAU statement on this topic:
http://laurelsplutoblog.blogspot.com/2013/02/responding-to-iau-pluto-an…

I don't know who you are, Wow, but your manners are boorish, at best. SEVERAL people have attempted to have a rational, reasonable discussion with you, which you responded with insults, profanity, and an authoritarian demand that YOUR understanding of the IAU decisions about Pluto mean.
After New Horizons flew past Pluto last year, the IAU was willing to concede it as a planet again.
Then, REALLY confuse the mix, there is now evidence of another planet, larger than Earth, orbiting out beyond the Oort Cloud, perpendicular to the other planetary orbits. This is one of MANY advantages that science has over religion. With religion, you have to fit new data or observations to preexisting definitions, while science changes definitions when new data presents. Stop being so close minded and insulting to those who disagree with you, and instead try to have a grown up discussion for once.

AndI don;t know (or care) who you are.

The “tone troll” is a real critter. They are the most common subspecies of Internet troll, mostly harmless but super annoying, and easy to spot in the wild: they complain about the tone of a message, rather than its substance. They fixate on the allegedly poor attitude of anyone who challenges them.

I neither ask you to like it nor emulate it.

You are all for free speech but only the speech mannerisms you like. Mannerism is part of speech, retard.

"After New Horizons flew past Pluto last year, the IAU was willing to concede it as a planet again."

No they aren't, liar.

You have NO proof of your claims, yet feel free to call people names, now calling me moron and liar. You think I'M the troll? Your laughable ignorance chows that you are both a troll and a bully.
Remember that free speech is NOT free from consequences. If you were face to face with me, talking as you have to the people on this page, your LEAST consequence would be a broken nose and fat lip. This is not your blog, you are not god and you are not the head of the IAU, so you don't get to decide what definitions of "planets" people use. Get off your high horse, and deal with people intelligently, or get out of your mom's basement and get a job.

@Aslan B #237:

Rather than thuggish threats of violence, a better response to Wow would have been supporting your claim with a link.

“After New Horizons flew past Pluto last year, the IAU was willing to concede it as a planet again.”

But aslan isn't here for reason. They're here to tone troll and, failing that, thug out.

The fact that this is the internet makes aslan an internet hard-man. Which is quite pathetic.

And rather ironic, is it not, that aslan's first words are "prove your claims" when, as you point out, he gave none.

Truly LOLworthy.

Aslan, if you tried to beat me up, I'd just kill you.

Even if you were bigger and stronger, you have to sleep some time. Then I'll nail you to your bed and set your house on fire.

And toast marshmallows (I don't like popcorn much).

I didn't bother to include a link, since that wasn't the point of my comment. The point was, and still is, that rather than discuss things with people RATIONALLY, you immediately start throwing insults. That was your response to me. From my first comment, rather than even trying to debate the points, you called me a moron. And your most recent comment about burning my house down proves the point that you are nothing more than a cheap-ass bully. Even through the course of "discussion" with Mike Wrathell and Laurel Kornfeld, you never once cited any actual proof of your stance, you just called them names. You don't get to act like a chimp throwing shit and then claim the moral high ground.
Even when others made the comment that the two of you would have to "agree to disagree" you hurled insults. That sort of authoritarian power-over does nothing to advance mankind's knowledge of the universe. It only seeks to subjugate others to your beliefs.
Now you are pissed at me for calling out your dishonesty and bullying. Good, stay pissed, your opinion are easier to discount when you act like Trump.

"I didn’t bother to include a link,"

Because you haven't any proof of your claim, asshat.

" since that wasn’t the point of my comment."

What? Without evidence you have an evidentless claim. And a tone troll.

So we can discard the claim that the IAU is considering Pluto a planet by any measure, and that the topic of the thread "Why there are (and should be) eight planets in the Solar System " was necroed by you to whinge at someone clearly your superior about something you have needlessly invested your self-esteem into.

Well done, moron,

No, I was not "Tone trolling" I was calling out a bully who is too big of a pussy to do anything other than insult people.
As for you being my superior, you are not even superior to dog shit, let alone any human being.
As for whether the solar system should have 8 planets or not, more recent discoveries, like "Planet Nine" should put that to rest.

(three links to information about Planet Nine, in case you want to bitch that I didn't prove that either)

Granted, that is a two and a half year old article, not post-New-Horizons, but even in October 2014, members of the IAU WERE discussing re-designating Pluto as a planet. As for the assertion in the article that there were "no plans to put it on the agenda" that means NOTHING. Many things end up on business or government agendas that nobody planned on adding.

So, again either discuss things as an adult or piss off.

Hey, moron, you COULD have just said that you think that Pluto should remain a planet. No evidence would be required, then. But, no, you decided to make shit up, then when asked (nicely by the bunny, proving that being polite to you is not a working strategy and therefore irrelevant to you), you blabbered about how it wasn't your point.

If your point was to make baseless claims, don't make that point.

Either discuss things as an actual grown up or fuck off.

Wow:

"Either discuss things as an actual grown up or fuck off."

LOL right, the king of childish behavior telling others to act like an adult. That's right up there with expecting billionaires to give a damn about working people. What a hypocrite.

"No, I was not “Tone trolling” "

Yes you were. Here's a more complete definiton since you seemcompletely clueless about it

http://rationalwiki.org/wiki/Tone_argument

The tone argument (also tone policing) is a logical fallacy that occurs when an argument is dismissed or accepted on its presentation: typically perceived crassness, hysteria or anger. Tone arguments are generally used by tone trolls (esp. concern trolls) in order to derail or silence opponents lower on the privilege ladder, as a method of positioning oneself as a Very Serious Person.

The fallacy relies on style over substance. It is an ad hominem attack, and thus an informal fallacy.

"do anything other than insult people."

100% provably false. This claim is liable to the "black swan" created, as it is, by confirmation bias and thoughtlessness from those whose mental capacities are unable to believe anything they were not previously open to believing.

I.e. you.

"And your most recent comment about burning my house down proves the point that you are nothing more than a cheap-ass bully."

Not one for introspection, are you aslan?

"Remember that free speech is NOT free from consequences. If you were face to face with me, talking as you have to the people on this page, your LEAST consequence would be a broken nose and fat lip"

Can dish it out, you just can't take it.

Isn't that the character of a bully?

@Wow #246: You don't seem to be one for introspection either. Anyone who points out your obvious incivility gets arbitrarily labelled a "tone troll," as though that makes you right.

Incivility, foul language, and ad hominem attacks are your stock in trade, and do much to weaken, obscure, and negate any sort of sensible points you might be trying to make.

It really doesn't matter whether you're "right" if no one bothers to notice your rightness in the midst of all your wrongheaded prickishness.

Wow;
"Can dish it out, you just can’t take it.

Isn’t that the character of a bully?"

Calling people moron and liar, a smack in your mouth it a consequence in keeping with the offense. Telling someone that you are going to commit murder and arson:

"Even if you were bigger and stronger, you have to sleep some time. Then I’ll nail you to your bed and set your house on fire."

is the act of a psychopath and a sociopath. But then, the fact that you respond to EVERYONE that disagrees with you with insults and threats, you being a sociopathic psychopath comes as no surprise.

Uh, "point out your obvious incivility" IS "tone troll". Look at the definition.

It isn't a rebuttal to the argument, it's an argument creating itself.

" ad hominem attacks"

You don't know what the meaning of that is either. Better find out what words mean before you thrown them at others.

"It really doesn’t matter whether you’re “right” if no one bothers to notice your rightness in the midst of all your wrongheaded prickishnes"

And that, again, is the definition of tone argument. See above link.

Maybe I don't do introspection, but you don't do it either.

"if no one bothers to notice your rightness "

You want to be right to massage your ego, mike. That's what the use of this wording says to me.

You don't have to read my posts.

You don't have to emulate them.

You don't have to like them.

You can write your own, even if it copies the argument I made.

Because I don't own the argument and evidence. Feel free to use yours and express it in the tone you prefer.

And extend the same courtesy to me.

Or wallow in your own perceived perfection over me and get told what the hell you're doing wrong in trying that yourself.

Sauce. Goose. Gandger.

Oh boy, happy ('f'n') new year !!!

And for gosh sake, PJ, mind your language!"

:-)

&lt voice="Captain America" &gt And for gosh sake, PJ, mind your language!" &lt /voice &gt

:-)

(see if the faux markup appears now...)

*sigh*

This'll cheer you up, bunny.

https://www.youtube.com/watch?v=YssrjLMNP_Q

Linky no work, try this on youtube:

watch?v=YssrjLMNP_Q

Sorry.

@251
Sorry, WOW, slip o'th'finger .....
;)

Heh. You meant F1, for "Help", not Fn. Makes serfect pense!

Oh look. Pee wee is back.

Hi coward!

Talking to yourself again, Wow?

No,aslan, I have no need to say "Hi" to myself.

If you were vaguely hominid in intelligence (instead of a knuckl-edragging merkin butthurt over the "scary change" of pluto not being a planet), this would not have had to be explained to you.

Unless of course you were trying to be childish... Ironic.

PS Pluto isn't a planet. Get over it.

Well, when you said "Hi coward" I figured you had to be describing yourself.

As for Pluto's status as a planet, that people have opinions that differ from your is something YOU have to get over. You are no authority, nor boss of this thread.

Irony.

Turning up with a monikker from children's story and complaining about "childishness".

Irony 2: More ironic.

Turns up to insult me specifically, make one asinine and unsupported claim, then threaten me and insult me again ON A THREAD LONG DEAD. And complains about "You never do anything other than be mean!".

Irony 3: Irony with a vengeance.

Demands that I piss off.

And says "YOU have to get over having no authority on this thread.

Truly you a a fucktard of EPIC proportions, you 12 year old little tit.

Now if you want to continue being a spoled and spiteful little brat, go over here where the one with authority on this thread tells you to go with that offtopic bullshit:

http://scienceblogs.com/startswithabang/2012/09/23/weekend-diversion-yo…

You lowlife little turd.

Where do Rogue Planets come from?

esiegel — Wed, 11 Sep 2013 15:37:51 +0000

Where do Rogue Planets come from?

"Like all animals, human beings have always taken what they want from nature. But we are the rogue species. We are unique in our ability to use resources on a scale and at a speed that our fellow species can't." -Edward Burtynsky

It's really a romantic notion when you think about it: the heavens, the Milky Way, is lined with hundreds of billions of stars, each with their own unique and varied solar systems.

Image credit: 湖北直行便 of AstroArts, via http://www.astroarts.jp/photo-gallery/photo/13870.html.

But beyond that -- in addition to the stars -- there are hundreds of billions of planets with no central stars at all: the rogue planets of our galaxy. We think this is true everywhere, from small star clusters to giant galaxies. As best as we can tell, there are at least as many starless planets wandering the cosmos as there are stars, meaning that for every point of light you see, there are probably more massive points that exist, but emit no visible light of their own.

Image credit: Southwest Research Institute.

We've recently discovered a number of possible rogue planet candidates, although since these are so difficult to detect (and are only visible from their heat signatures in the infrared) we know that there must be many, many more than what we've seen so far. You can't help but wonder where these rogue planets come from!

One compelling source is near and dear to us all.

Image credit: Axel M. Quetz (MPIA).

We know how solar systems like our own form: you get a central star with a protoplanetary disk around it. Gravitational perturbations in the disk attract more and more matter from their surroundings, while the heat from the newly formed central star gradually blows much of the lightest gas away into the interstellar medium. Over time, these gravitational perturbations grow into asteroids, rocky planets, and eventually -- for the largest ones -- gas giants.

Image credit: NASA / JPL-Caltech.

The thing is, these worlds don't just orbit their central star, they also gravitationally tug on one another! Over time, these planets migrate into the most stable configurations they can attain, and this usually mean the largest, most massive worlds migrating into their most stable configurations, often at the expense of other worlds.

A recent simulation shows that for every planet-rich solar system like our own (with gas giants) that forms, there's likely to be at least one gas giant planet that gets kicked out, into the interstellar medium, where it's doomed to wander the galaxy on its own as a rogue planet.

Image credit: NASA / JPL-Caltech.

That's almost definitely a major source of rogue planets.

But here's the funny thing: when we work out the numbers of our best theoretical calculations, it's far less than 50% of all rogue planets that are expected to be accounted for by this process. To figure out where the majority of starless planets come from, we have to look at a larger scale at around the same time: not just when the Solar System formed, but at the cluster of stars (and star systems) that all formed at around the same time!

Image credit: ESO / R. Chini, from the ESO's Very Large Telescope.

Star clusters form from the slow collapse of cold, mostly hydrogen gas, typically within a galaxy. Within these collapsing clouds, gravitational instabilities form, and the earliest, most massive instabilities preferentially attract more and more matter. When enough matter gets together, and the densities and temperatures at the core of these clouds get high enough, nuclear fusion ignites!

Image credit: Joseph Brimacombe.

This results in new stars and star systems, but something else happens, too. The biggest stars that form are also the hottest and bluest, meaning they emit the most ionizing, ultraviolet radiation.

So when you look inside a star-forming nebula in the Universe, you are actually watching two processes simultaneously competing:

Gravity, as it attempts to pull matter in towards these young, growing gravitational overdensities, and
Radiation, as it works to burn off the neutral gas and blow it back into the interstellar medium.

Who will win?

Image credit: Sid Leach of the Eagle Nebula, via http://www.sidleach.com/m16.htm.

It depends what you mean by "win," exactly. The biggest gravitational overdensities form the largest stars, but these are also the rarest of all stars. Smaller (but still large) ones form the other star types, but become more and more common as we get down to lower masses. This is why, when we look deep inside a young star cluster, it's easiest to see the brightest (blue) stars, but they're vastly outnumbered by lower mass, yellow (and especially red), dim stars.

Image credit: Sloan Digital Sky Survey, of Messier 67.

The thing is, if it weren't for the radiation, there dim, red-and-yellow stars would have grown more massive, brighter, and burned hotter! Stars (on the main sequence, which is most stars) come in a variety of types, O-stars being the hottest, largest and bluest and M-stars being the coolest, smallest, reddest and least massive.

Image credit: Wikipedia user Kieff.

Even though the vast majority of stars -- 3 out of every 4 -- are M-class stars, compared to less than 1% of all stars being O-or-B stars, there's just as much total mass in O-and-B-stars as there are in M-stars.

And it turns out that some 90% of the original gas-and-dust that was in these star-forming nebula gets blown off back into the interstellar medium rather than forming stars. The most massive stars form the fastest, and then get to work blowing the star-forming material out of the nebula. By time a few million years go by, there's less and less material to form new stars at all. Eventually, all the leftover gas-and-dust will burn off completely.

Image credit: NASA and The Hubble Heritage Team (STScI/AURA).

Well, guess what? Not only are M-class stars -- stars between 8% and 40% of the Sun's mass -- the most common type of star in the Universe by far, but there are a whole lot more that would have been M-class stars if it weren't for the high-mass stars burning off this material!

In other words, for every star that forms, there are many, many failed stars that didn't quite make it; anywhere from tens to hundreds-of-thousands of them for each star that actually forms!

Image credit: Greg Stewart / SLAC National Accelerator Laboratory.

These nomad planets -- or rogue planets -- may or may not have atmospheres, and they may be incredibly difficult to detect, especially the (theoretically) more common ones: the smallest objects.

So we may have a few rogue planets that were ejected from young solar systems, and there may even be a couple that came from our Solar System, but the vast majority were never attached to stars at all! Rogue planets wander the galaxy, most of them to toil forever in loneliness, never knowing the warmth of a parent star, thwarted by stellar evolution from ever becoming stars themselves. What we have, instead, is a galaxy with trillions or possibly even quadrillions of these nomad worlds, objects which we're only just beginning to discover. And that's where rogue planets come from!

esiegel Wed, 09/11/2013 - 11:37

Tags

So are the masses of the Roque Planets taken into account in the tally of the mass of the Universe ? Are they part of the 4 % ? What is the best estimate for the mass difference between "trillions " and "quadrillions" ? Thanks.

Is there a reason for the power law that says that each class of stars has roughly the same total mass? It seems unlikely to be coincidence, yet there doesn't appear to be any obvious reason why there should should be any scaling law, let alone one that is so orderly.

In the hypothetical case of a gas giant booted out of its orbit by Jupiter, why is it so obvious that it would be totally expelled from the solar system? Couldn't it still remain in a very distant orbit?

Wow! Like using exclamation points, much!

Yes, a gas giant thrown into the far reaches of the solar system can get stuck there (identical to how we produce Oort cloud comets), but the chance of that happening is only a couple percent. So - probably not, unless there were dozens.

@ 1

The mass of any rogue planet compared to 1 solar mass is extremely tiny. Given a galaxy you might at best get 0.1% contribution. And yes, they are in 4% part since they are made of matter like everything else.

@2
yes, you can check stellar classification. Basically it's like black body radiation. Different colors, different temperatures hence energies, hence composition, hence mass needed to produce such and such radiation.

SL, re answer to #1, it would be more complete and helpful to say that it is part of the 4% because it will, despite being "dark", it interacts with normal matter and can be captured like normal matter. It is also able, since it is a coalesced body of significant size, be able to spot a significant portion by their occlusion of starlight.

True Dark Matter (tm) doesn't interact even with itself well and therefore doesn't coalesce and, if it reacted with photons (the idea is it would not, any more than it would with normal matter, but if it did, it would be pushed out of every stellar envelope by photon pressure), it is a diffuse body and does not cause extinction in the same way.

And like Velikovsky said, when a HUGE object (we are calling them rogue planets here) comes into the influence of a star, it becomes a comet. As Jim McCanney says, the object then discharges the Solar Capacitor like a bug zapper. This causes the Sun to begin to increase its activity. The bigger the object, the more the solar activity. We do not see HUGE comets the size of Venus too often, luckily, but we have had them pass nearby on occasion. They are usually very destructive and can account for massive Earth changes simply by passing near by, without impact. Like Velikovsky proposes, Venus was a comet before it fell into its present orbit. It happened in recorded history and caused people to go underground at the time it passed by us, possibly 4K years ago. Venus even exhibited a tail.

@ Wow

Well, I did say it :) "And yes, they are in 4% part since they are made of matter like everything else."

you must have missed it.

@3: It's possible for a planet to be kicked into an orbit which is highly elliptical but still bound. To do that, you would have to boost its speed to somewhere between the circular orbit speed and escape speed for its previous location. IIRC, these two speeds differ by a factor of sqrt(2). The problem is whether such a planet would remain in that orbit without having nasty effects on the planets remaining in more conventional orbits whenever this planet approaches periastron. Near apastron, it wouldn't take much of a gravitational kick from a nearby star to turn this planet into an Oort cloud object (similar to how Oort cloud objects become comets), or finish the job of kicking it out of the solar system. Alternatively, the remaining planets could finish the job when this planet next approaches periastron.

No, you said it but it was implied, not explicit.

All you said in explicit form was "it's not like dark matter because it's like the regular matter".

You never explained why it would be known to be part of the 4% of normal matter and not part of the 20-ish% of dark.

Just said it wasn't.

true, it was implied, because Ethan's article is about it. Since they are made of the stuff that was in our solar system.

Didn't think @1 was asking if they were DM, rather if their mass contribution was accounted for in normal matter. Guess it's how you interpret the question. Anyways you added more to the answer so it's all cool :)

"Since they are made of the stuff that was in our solar system. "

sorry.. should be our/other solar system.. hence hydrogen, rocks, metals etc...or just gas giants

"Didn’t think @1 was asking if they were DM,"

That's how I read it.

Use the term rogue planet and the cranks come running in, as displayed by wally58 above.

I believe the theoretical argument that they should form, but what direct observation is there that they do form?

@16

not likely to get "direct observation" any time soon. Think about it. How do you observe a tiny speck that doesn't emit light.. hence black.. against a black background of space?

It will be a major breakthrough when we get to "directly observe" any planet outside of our solar system. Those wandering the blackness of space.. who knows.. maybe in some other bands if they emit something.

"How do you observe a tiny speck that doesn’t emit light.. hence black.. against a black background of space?"

I'm reminded of the conversation aboard Hot Black Desiato's ship with this...

I believe a few months ago we have the first direct observation of an extrasolar planet.

Though that might have been the observation of the absorption spectra of a planetary atmosphere (dense enough neutral matter to be neither space dust nor stellar atmosphere).

@Wow #19: Direct observation of extrasolar planets goes back several years, to at least 2004. HR8799's four planets were imaged back in 2010; AB Pictoris has a companion which is either a brown dwarf or Jovian-mass planet, directly imaged in 2003. See http://en.wikipedia.org/wiki/List_of_directly_imaged_extrasolar_planets for a current list.

Thank you Michael! This is awesome. To this day I wasn't aware that this was done.

Read the paper on GJ 504. Awesome! A real image of a planet orbiting some other sun. So cool!

p.s. Ethan, why no article on that we are actually able to image exoplanets?? :D Bad Ethan!! :))

Well, I remembered a story a few months ago (earlier this year anyway) and may have been about the direct measuring of the atmosphere of the planet rather than imaging the planet directly.

Rogue planets came from bad family backgrounds?

@Wow #23: Ah! I think you're remembering the recent spectroscopic analysis of HD 189733b (http://en.wikipedia.org/wiki/HD_189733_b).

A study of the combination of absorption features derived for the planet from secondary eclispes allowed the authors to "estimate" the apparent color the planet would have if we could see it directly.

No exoplanet has yet been imaged in "true color," although, given the progress in the field, that is only a matter of time.

Probably is, Mike.

Everyone: ferocious criticism invited for the following:

Are there any estimates of (or any reasonable basis for estimating) the occurrence of approximately-Earth-mass rocky rogue planets?

Those might be useful for interstellar colonization as follows:

1) Locate Earth-sized rogue planet.
2) Build Dyson rings around two or more of its nearest suitable stars.
3) The Dyson rings capture energy from the stars and convert to microwave laser or similar means, directed toward artificial moons (or captured space rocks with infrastructure built) orbiting the rogue planet.
4) At the moons, incoming energy is converted to a form that can safely be beamed down to the planet's surface and used.
5) Meanwhile, the Dyson rings are inhabited by minimal populations needed to maintain them. These should be small enough populations as to easily migrate off the Dyson rings to the client planet when the stars became hazardous toward the end of their useful lives.

Why go through all that effort, when there are Earth-sized planets orbiting stars, that can be colonized?

Because then you have an inhabitable world that is not a) dependent on and b) at risk from, a single star. Its usable lifespan would be equal to the useful life of the most long-lived of the stars that provided it with energy. Assuming you need at minimum two stars to supply energy to a rogue planet, build Dyson rings around a total of three or more stars, and you have time to replace any of them that are lost in stellar explosions.

Also it would seem that rogue planets in and of themselves, could potentially have the raw materials needed to support life, but be lifeless due to lack of energy sources. Thus they are ready to colonize with zero to minimal risk of encountering indigenous microbes that could prove fatal.

Comments?

G: even for sci-fi, your proposal is extremely Rube Goldberg-ish. Any civilization that can do step 2 has no need of any of the other steps; it can simply move to another system when the old star is close to burning out.

Secondly, wouldn't it just be easier to locate a rogue planet with some internal heat associated with it, and just use that? Whether gas giant or rocky, the rogue planet's gravitational force on its own mass will tend to heat things up at depth. I have to think that extracting that heat as work must be a great deal easier than your set-up. A jupiter-sized geothermal generator is (speculatively) peanuts compared to ringworlds firing interstellar lasers.

NASA Astrobiology Roadmap 5: Planetary Conditions for Life

catdynamics — Mon, 20 May 2013 13:30:12 +0000

NASA Astrobiology Roadmap 5: Planetary Conditions for Life

The final session in the online discussion of the NASA Astrobiology Roadmap is today from 4-5 pm eastern.

Go to Astrobiology Future to sign in to the live web chat. Questions and comments will be taken both from call-ins and from written questions.

The online discussion will be moderated by Dr Francis McCubbin from UNM, Dr Sean Raymond from Laboratoire d'Astrophysique de Bordeaux, and yours truly...

The live session will, as with the other Roadmap sessions, be followed by a week long opportunity to input questions, ideas and topics for discussion at The Astrobiology Future Forum.

Is life a chemical consequence of thermodynamics or did it emerge in spite of thermodynamics?
Will we ever be able to uniquely identify fossils of microorganisms in the rock record of another planet given the absence of biologically exclusive chemical and morphologic signatures?
Organic molecules can be produced a wide variety of inorganic chemical processes, what geologic conditions are needed to promote the concentration and complexification of organics towards abiogenesis?

What factors determine the amount of water delivered to planets in a star's habitable zone and the availability of that water for participation in chemical reactions?

Water delivery to the inner planets for different planetary system configurations: Raymond, Mandell & Sigurdsson

As I have noted before, it is critically important that the community in general, and junior researchers in particular, provide input, questions and ideas.
If you don't, I'll decide your research priorities for you.
So there!

Giant Intelligent Squid!

catdynamics Mon, 05/20/2013 - 09:30

Tags

Is There Life on Maaaars?

cevans — Tue, 12 Mar 2013 18:53:12 +0000

Is There Life on Maaaars?

You certainly didn't hear it here first: today NASA, at a press briefing, announced that minerals analyzed by the Curiosity rover indicate that life might, in the galactic past, have survived on Mars. The rover's been poking around an ancient network of stream channels descending from the rim of Gale crater since September of last year; now, after drilling into the sedimentary bedrock nearby, it's hit on a treasure trove of life-supporting minerals: carbon, oxygen, hydrogen, phosphorus, sulfur, and nitrogen. These mineral findings are really just icing on the cake, as the geological clues–fine-grained mudstone streaked with nodules and veins, the telltale drifting forms of a past sometimes wet–already spoke volumes.

To answer your question, David Bowie, no, this doesn't mean that Curiosity scientists found life on Mars–only conditions suitable for it to exist. This is only the discovery of a setting, the stage for a primeval drama. But it's still impressive. Mars is a huge planet and the Curiosity rover is a small, plodding thing, which cuts an unassuming profile as it diligently sifts through the dust. It moves gingerly across the landscape. It is a laborious little laboratory, and Mars is a huge jarring vista of red under a harsh, dark sky.

These discoveries, although tantalizingly vague, are testament to the power of properly applied technology: against all odds, on a distant planet we can only dream of visiting ourselves, Curiosity's fiercely economical little corral of tools, leveraged in just the right manner, can reveal magnitudes. Pretty cool.

John Grotzinger, Mars Science Laboratory project scientist from the California Institute of Technology, celebrates the discovery of an ancient environment so benign that "probably if this water was around and you had been there, you would have been able to drink it." It's a satisfying mental image: instead of a souped-up golf cart preciously vaporizing pellets of rock, imagine scooping handfuls of Martian water from streams long since run dry. Your thirst slaked, you brush the red dust from your knees and stand to see the Earth, a significant blue dot on the horizon.

cevans Tue, 03/12/2013 - 14:53

Tags

Bullet Proof Shocking Photo Evidence for Life On Mars...
My channel on u-tube..eagleman725
Thank You
Antony

"I'M SIGNIFICANT!"

screamed the speck.

Can we determine life in other planets or moon by send some organic materials there? If organic materials undergo decay process, can we conclude that there are bacteria or some organism that carry out the decomposition? For example, can we crack an egg and observe what happens after a period of time?

The Universe is Alive

esiegel — Fri, 08 Feb 2013 16:29:41 +0000

The Universe is Alive

"Night, when words fade and things come alive. When the destructive analysis of day is done, and all that is truly important becomes whole and sound again." -Antoine de Saint-Exupery

When you look out into the Universe, what is it that you typically think of? Do you think of reliable, fixed stars and constellations? The vast expanse of the Milky Way, with its memorable dust lanes and amorphous shapes?

Image credit: Wally Pacholka of http://www.astropics.com/.

The unchanging nature of the points of light in the sky?

Image credit: Roth Ritter (Dark Atmospheres), of the double cluster in Perseus.

Maybe you think deeper and farther than that. Maybe you think about the distant galaxies and clusters, and the deepest deep-sky objects we know of. How the light took millions or even billions of years to reach us, and yet how every time we look at them, we see them exactly the same way.

Image credit: Misti Mountain Observatory.

I couldn't fault you for thinking like this; from mankind's point of view, the Universe -- for all intents and purposes -- doesn't change at all as we view it from one night to the next.

But does that really mean the Universe isn't changing?

Let me flip this around on you: how much does anything here on Earth -- you, your surroundings, even an entire, vibrant city -- change in half-a-millisecond?

Image credit: DC User Forum, of a short-exposure shot with a Sony A900 DSLR.

Not a whole lot, that's for certain. You only change with the passage of time, and half-a-millisecond is just 0.00000000002% of a typical human lifetime. It's too short of a timespan to notice any but the most catastrophic changes, and even then you have to look very closely.

So why should you expect the Universe to change substantially over just 0.00000000002% of its lifetime? That's how much of the Universe's lifetime passes between one night on Earth and the next. And yet, if you looked at the right objects, you would be able to see meaningful changes from one night to the next.

Image credit: Tunc Tezel.

The objects within our Solar System, for example, are close enough that we can see them moving from night-to-night. Objects closer to us -- like Mars, in the foreground -- appear to move more substantially than more distant objects like Uranus, visible in the background.

The great cause of all this motion, of course, is our largest nearby clump of matter: the Sun. Objects like planets move at tens of kilometers-per-second relative to the Sun thanks to its gravity, while Sun-grazing comets can be accelerated up to speeds in the hundreds of kilometers-per-second. If you're in the southern hemisphere, you may be able to get a good view of one now: Comet Lemmon.

Image credit: Rolf Wahl Olsen from Auckland, New Zealand.

Green because of the carbon and nitrogen interacting with sunlight, this photo does an excellent job of tracking the stars from the Earth along with the Earth's rotation. What you probably can't tell is that the comet -- with a photo exposure time of over an hour -- is blurred.

If instead of tracking the stars perfectly, we tracked the comet perfectly, know what we'd see?

Image credit: Peter Ward (Barden Ridge Observatory).

That comet is moving relative to the stars behind it, and our ultra-close proximity to the comet makes it abundantly clear.

But what you may not realize is that these "fixed" stars are also moving at tens-to-hundreds of kilometers-per-second relative to us, and relative to one another! It's only the vast distances between us -- measured in many light-years -- that make it impossible to detect these changes from night-to-night.

But we can't really detect changes in ourselves from millisecond-to-millisecond; you simply need to look on longer timescales!

Image credit: Martha Haynes of Cornell University.

The stars in our night sky shift positions by many kilometers each second. From night-to-night we might not be able to tell the difference, but just as you or I look different when we go weeks without cutting our hair, we can see just how the Universe changes over long enough timescales.

There are gas clouds and stellar remnants tearing through the interstellar medium at these same speeds, including some that move at thousands of kilometers-per-second, even approaching 1% the speed of light!

Image credit: NASA/ESA/Hubble Heritage Team and CTIO.

There are new stars being born -- where nuclear fusion ignites for the first time -- and stars that run out of fuel, dying in either a planetary nebula or a supernova explosion, depending on the properties of the star.

Image credit: http://astrojan.ini.hu/, retrieved from Margaret Hanson, U. of Cincinnati.

And on the largest scales, galaxies merge together, triggering star formation and some fabulous cosmic mashups, in processes taking upwards of hundreds-of-millions of years.

Image credit: Hubble Space Telescope, NASA, STScI and ESA.

And in some of the fastest and most spectacular changes, catastrophic stellar events -- like supernovae -- can literally appear from nothing over the timescale of just a few nights!

Image credit: Peter Nugent/Palomar Transient Factory.

When you look up at the Universe, it may appear static and unchanging, but that's only because these objects are so far away and our human experiences are so short in comparison with the age of the Universe.

But stick around for a while, and even the most mundane of objects will change for you. Fuel burns, elements fuse, gravity pulls, and physics happens. Just give it time, and you'll see it for yourself.

We may only be around for a snapshot of it, but make no mistake, it's never the same from moment-to-moment. From the way I look at it, there isn't any doubt about it: the Universe is alive.

esiegel Fri, 02/08/2013 - 11:29

Tags

What do you mean by "alive", "universe" and "is".

Are elementary particles alive too?

What do you mean by "clarity", "please" and forgetting that a full stop doesn't indicate a question?

Great article. I'm sorry that you're about to receive a bunch of comments taking you out of context with the whole "Universe is alive" thing. It seems obvious that you're not stressing this in a literal sense and that you're simply implying that the Universe is more dynamic that it appears to us from our limited vantage point in space and time.

Thinking about the Universe in a dynamic sense is what makes science so exciting for me, personally. Abstracting the intricacy of the world around us into a static and unchanging picture has never done science any favors, in my opinion.

I am sitting here pleased to be in a living universe. I think that means it is not surprising to find intention and purpose somewhere in it and indeed we do find that. The time scales of things are essential.

Also the size matters.

As far as life goes, it is single cell life that is by far the most successful on the planet by several measures and it is only our pride that keeps us from realizing we people as organisms are basically colonies specialized to many purposes, most of them not ours at all.

The life cycle of stars is so completely foreign that we can't see it at all.

Humankind is startlingly good at denial and insisting on the illusion of central position. We cannot really find our place in the grand scheme of things without breaking free of both.

De acuerdo con Zacarias entiendo no es literal "esta vivo" sino que esta en movimiento o es dinámico ademas no olvides que cuando miramos el universo, dadas las magnitudes de las distancias estamos mirando el pasado no el presente y en algunos casos miramos incluso "fantasmas" es decir eventos que ocurrieron hace miles de millones de años y hasta ahora nos llegan las imágenes de tales eventos, por poner un ejemplo la explosión de una estrella un evento que, dependiendo de la distancia (en años luz) que le separe de nosotros así también es la distancia en el tiempo en el pasado en el que tuvo lugar tal suceso o evento.

Ethan, another great blog.
A property of being alive is that you can attempt to multiply. It kind of funny, but probably no coincidence, how the universe tackles the task - and your image supports the claim: http://scienceblogs.com/startswithabang/files/2013/02/eternal_inflation…
Keep writing!

Cosmic mitosis:
"In physics, the intriguing concept of baby universes as the oﬀspring of a parent universe – acquiring a life of their own while remaining connected to the latter – has been most concretely realized in 2d Euclidean quantum gravity models... Our key observation will be that the necks of baby universes are by construction rather special curves on the two-surface, whose scaling behaviour (as function of the surface area A) is diﬀerent from that of generic curves... The shortest non-contractible loop based at any given vertex v can be found by performing a so-called breadth-ﬁrst search along the edges starting at v... No matter what choice one makes, additional weights associated with the matter on the boundary will arise, which are simply not taken into account in the treatment of, which crucially features “baby universe surgery” along such boundaries." arXiv:1110.3998

Cosmic consciousness:
"Sensible Quantum Mechanics or Mindless Sensationalism is a framework for relating consciousness to a quantum universe... Sensible Quantum Mechanics assumes the connection between consciousness and the quantum in the form that for each conscious perception p, there is an associated quantum “awareness operator” A(p), and that the measure for the conscious perception p is the expectation value, in the quantum state of the universe, of the corresponding experience operator, w(p) = σ[E(p)]." arXiv:1102.5339

Cosmic depression:
"The Cosmically Depressed: Life, Sociology and Identity of Voids... Void Life: Formation and Evolution... In summary, it allows us to ﬁnd the emptiest regions and most lonely galaxies in the Local Universe." arXiv:0912.3473

Does the universe needs a shrink?

Part of it clearly does, yes.

(You know, I'd even bet that you're not a real angel, nor called Gabriel. Just a hunch.)

The Big Dipper is going away in 100.000 years? I will worry about it when it happens.

"Cosmic Voids and Galaxy Bias in the Halo... we make the conventional simplifying assumption that.. HOD is independent... void(s).. can reduce systematic uncertainties in the cosmological constraints derived from HOD... Voids are.. omnipresent... Even in the deepest voids in the dark matter, halos still form... Void(s).. are, however, sensitive to differences in the minimum halo... Because they are sensitive to environmental variations of the HOD... galaxies.. effectively "shrink" the voids." arXiv:astro-ph/0603146

Well I was just sitting there on the head of a pin with the other angels observing that, yes of course, there are more angels on the head of a pin than even electrons.

Then Archangel Raphael sat down beside me and suddenly remarked, "Make no mistake, it’s never the same from moment-to-moment. From the way I look at it, there isn’t any doubt about it: the electrons are alive." He spoke with such poetic certainty.

Moved, I kindly inquired, "Really?"

Raphael rasped, "Like me, the reports that electrons are dead are greatly exaggerated."

I fumed, "Now how didn't I know."

Nice post Ethan. I needed that to remind me of a few things.

When we look at the universe, we are looking at the past, millions and billions of years ago. In our very short span of life, how could we know what is happening to the the universe "now", our definition of this very moment, let alone in the far "future"?
(btt1943, tanboontee)

Really liked the Mars/Uranus pic!

@tanboontee
"In our very short span of life, how could we know what is happening to the the universe “now”, our definition of this very moment, let alone in the far “future”?"

Well for starters, the idea that there is a well-defined "now" that applies to the whole universe got thrown out with Relativity. Also, it is literally impossible to know what is happening "now" somewhere else because information about their "now" can't reach us faster than light ergo the "now" we witness here is always the "past" for the distant object.

However the reason why we can have a pretty well educated understanding is because of exactly what you said -- we're looking at the past, millions AND billions of years ago. And tens of thousands of years ago, and a few years ago. We can see many epochs of the history of the universe by looking at objects at different distances.

We have to assume that the past of our neighborhood of the universe is well-represented by the "now" of distant objects. But doing so presents a coherent picture of the universe, so it seems to work. And by studying that picture, and learning the rules that govern its evolution, we can make reasonable predictions about the future.

In other news, some people need to look up "alive" in the dictionary and understand there are more meanings that the "biological life" sense.

Meaning is determined by context.

Google and find the meaning-in-context of the phrase: the universe is alive (no quotes used)

The resultant page 1 meanings (usage examples) are:

"The cosmos may be a superorganism, a collection of separate bodies acting like a single being."

"Scientific Evidence of a Living Consciousness Universe"

"Is the universe alive? Does it evolve, think, reproduce?"

"Computer Model Shows the Universe is Alive!"

"The Universe is fundamentally biological."

Yes, Ethan phrase must deliberately provokes one of these meanings which I hadn't considered. Hmm?

Maybe the relevant similar example to Ethan's usage can be found beyond page 173 of google's search results.

Google is wonderful for geeks seeking an example of similar word usage.

But which example is most similar to Ethan's usage? Hmm? I'm not sure.

So your claim is that to understand the context of Ethan's usage, you shouldn't consider the context surrounding the phrase in question, as in what he wrote, but rather a bunch of out-of-context search results from googling "universe is alive"? You'll have to try harder to get me to buy that.

You know why? Because the top google results for "buy" have nothing to do with the meaning you automatically gleaned from the actual context in which I used that word.

Oh well. At least you're keeping the discussion alive.

This article has changed my view on the universe. Though I've never been a habitual star-gazer, the few times I have spent a night looking at the stars have all seemed the same to me. I can usually find my favorite constellations with ease among the scattered stars, and even though I've known that things change in space, I never realized that the stars do as well. When you compare it to how a persons hair length changes day after day, it really sinks in that small changes in the galaxy can easily go unnoticed. And even though the universe does not evolve, think, or reproduce (as said in previous comments), the world 'alive' is refering more to the vast unknown possibilities it encompasses. There's so much to learn about it and everything in it, and the fact that it is constantly changing opens up endless possibilities.

Oh, you've got to be kidding me.

Ethan Siegel now is saying that the Universe is alive? And about a year ago, is specifically quoted as saying this about a theory proving that the universe is alive:

"Or in the words of astrophysicist Ethan Siegel at Lewis and Clark College (and author of the blog Starts With a Bang), 'Crackpottery doesn't even begin to describe just how dreadful this is, and how much shame should be heaped upon CWRU for this."'"

see here:

http://www.livescience.com/18207-crackpot-theory-reveals-dark-side-peer…

So, a theory that proves that the universe is alive is "crackpottery" according to Ethan, but its ok for him to use bunch of pictures to make the same claim. Geez, contradict yourself much, Ethan?

How about this: The terms information and life are mushy and a bit ambiguous, but a search of the terms information and life will produce abundant evidence that information and life, whatever they may be, can not be separated. The universe is definitely quantum in nature --- again whatever that may mean. The current knowledge of the relevant fields shows that according to quantum mechanics information can not be created nor destroyed.

Thus, how, exactly can one avoid the conclusion that the universe is alive, by whatever definitions one wishes to use?

i like this

The universe is literally alive! It was born, it'll live for a time and die, just like everything else. Imagine a virus in the host body. Then, that virus trying to see its total surroundings. That's humans and the universe. If it sounds simplistic, it's because it's that simple..

Viruses don't have eyes and therefore can't see. Not having a nervous system or storage for those impulses, they also can't consider. Not to mention there's no reason for the universe to know itself either: it has no discernable want or need. We anthropomorphise things, because pretending agency even when there is none is a benign false positive for survival whilst failure to predict agency is a dangerous false negative. I.e. if the noise in the bush is just random, thinking it may be a predator is moving is healthy alarm, even if it's not, but if you dismiss it as mere happenstance when it isn't, you're liable to be something's lunch.

But because it's a survival technique it means it doesn't really prove agency wherever we consider it to be. Because it never had to evolve accuracy.

The universe is as literally alive as the English language is. As in "in a figurative sense". We have nothing to conclude otherwise. It really is that simple.

How Many Planets Are In The Universe?

esiegel — Sat, 05 Jan 2013 12:45:48 +0000

How Many Planets Are In The Universe?

"Stuff your eyes with wonder, live as if you'd drop dead in ten seconds. See the world. It's more fantastic than any dream made or paid for in factories." -Ray Bradbury

It wasn't all that long ago -- back when I was a boy -- that the only planets we knew of were the ones in our own Solar System. The rocky planets, our four gas giants, and the moons, asteroids, comets, and kuiper belt objects (which was only Pluto and Charon at the time) were all that we knew of.

Image credit: NASA's Solar System Exploration, http://solarsystem.nasa.gov/planets/index.cfm.

But these were just the worlds around our Sun, which houses (according to current definition) eight planets. Our Sun is just one of an estimated two-to-four hundred billion stars in our Milky Way galaxy, and looking up towards the night sky, one can't help but wonder how many of those stars have planets of their own, and what those worlds are like.

Image credit: Free Roaming Photography, by Mike Cavaroc.

There are a vast variety of stars out there in our galaxy. Our Sun is just one example -- a G-class star -- of seven different main types.

Image credit: Wikipedia user Kieff; annotations by me.

We may think of our Sun as being typical and on the relatively dim side, since a disproportionate number of stars visible to our eyes in the night sky are O, B, and A-class stars. But in reality, the Sun is more massive and intrinsically brighter than 95% of stars in our galaxy. The red dwarf stars -- M-class stars -- which are no more than 40% the mass of our Sun, make up 3 out of every 4 stars that are out there.

What's more than that, our Sun exists in isolation; it is not gravitationally bound to any other stars. But that is not necessarily how stars exist in the galaxy, either.

Image credit: VISTA infrared survey, ESO / J. Borissova.

Stars can be clustered together in twos (binary stars), threes (trinaries), or groups/clusters containing anywhere from hundreds to many hundreds of thousands of stars.

My point is this: if you want to accurately estimate how many planets there are in our galaxy, you can't just take the number of planets we find around our star and multiply it by the number of stars in our galaxy. That's a naïve estimate that we'd make in the absence of evidence. But just for fun, that'd give us somewhere around two-to-three trillion planets in our galaxy. And as we know from our own Solar System, there's a great variety of what the surfaces of those planets could look like.

Image composite: credit Mike Malaska. For individual image credits, see lower left.

But over the past two decades, we've been looking. We've been looking with a few different methods, in fact, and the two most prolific are the "stellar wobble" method, where you can infer the mass-and-radius of a planet (or set of planets) around a star by observing how it "wobbles" gravitationally over long periods of time:

Image credit: European Southern Observatory.

And the transit method, where the light coming from a distant star is partially blocked by the disk of a planet in its solar system passing in front of it.

Image credit: ESA / NASA's Solar And Heliospheric Observatory (SOHO), 2006.

It's important to recognize, when we do this, that we will not see the vast majority of planets that are out there. Take NASA's Kepler Mission, for instance, which has discovered hundreds (if not thousands) of planets by looking at a field-of-view containing around 100,000 stars. But that does not mean that there are only a few planets-per-hundred-stars. Consider the following: if Kepler were looking at our Solar System, and our Solar System was oriented randomly with respect to our perspective, these are the odds that the alignment would be good enough to observe a transit of our star by one of our planets.

Planet	Degree Range (out of 180)	% chance of good alignment
Mercury	1.37 degrees	0.76% chance
Venus	0.738 degrees	0.41% chance
Earth	0.533 degrees	0.30% chance
Mars	0.320 degrees	0.18% chance
Jupiter	0.101 degrees	0.056% chance
Saturn	0.0556 degrees	0.031% chance
Uranus	0.0277 degrees	0.015% chance
Neptune	0.0177 degrees	0.0098% chance

Now you may think those are not-so-good odds, but you don't even know the half of it. Mercury and Mars are too small, meaning they don't block enough of the Sun's light, to be detectable with Kepler, and the four outer planets, despite their large sizes, take too long to orbit for Kepler to observe more than one transit, a necessity for a planetary candidate.

So this means that if Kepler were looking at 100,000 stars identical to our own, it would have found 410 stars with a total of 700 planets around them.

Illustration credit: NASA / Jason Rowe, Kepler Mission.

But as of today, Kepler has found over 11,000 stars with at least one planetary candidate, and over 18,000 potential planets around those stars, with periods ranging from 12 hours up to 525 days. In other words, there are:

a huge variety of planetary systems out there, most of which are very different from our own,
orbiting a wide variety of stars, including binary and trinary systems,
and we are only seeing the ones that are large enough, orbiting their stars close enough, that also have unlikely, fortuitous alignments with respect to our line-of-sight.

You may have read this week that there are at least 100-to-200 billion planets in our Milky Way, and that's true, but that's not an estimate; that's a lower limit. If you instead were to make an estimate, you'd get a number that's at least one (and more like two, if you're willing to make inferences about outer planets) orders of magnitude higher: closer to ten trillion planets in our galaxy, alone!

Image credit: ESO / M. Kornmesser.

In other words, based on what we've seen so far, most stars are likely to have planets, and based on what we've seen in the inner solar systems of the ones that do, a large fraction of them are likely to have more rocky planets in their inner solar systems than even our own has, to say nothing of the outer solar system!

Image credit: J. Pinfield / RoPACS network / University of Hertfordshire.

This doesn't even include orphan planets (without a parent star), which we know exist, even if we don't know their numbers yet. Over time, we'll continue to learn more and refine our estimates, but right now, there are at least about as many planets as there are stars in our galaxy, and quite possibly many, many more than even eight times that number.

Our solar system may turn out to be average, slightly above average, or somewhat below average; we're still not sure. But regardless of which way it goes, we're talking about trillions of planets in our galaxy alone. And remember, our galaxy isn't alone in the Universe.

Image credit: NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team.

With at least 200 billion galaxies out there (and possibly even more), we're very likely talking about a Universe filled with around 10²⁴ planets, or, for those of you who like it written out, around 1,000,000,000,000,000,000,000,000 planets in our observable Universe.

That number's only going to get more accurate, but I'm tired of people giving the lowball-estimate when it's eminently likely that there are so many more. Let's keep looking, for not just planets, but for water, oxygen, and signs of life. With all of those chances, we're bound to get lucky if we persevere and look hard enough!

esiegel Sat, 01/05/2013 - 07:45

Tags

ouch!...it hurts my head but it's so good! Thanks Ethan again

Fermi's Paradox doesn't seem like much of a paradox to me.

However, I sometimes wonder if the irony might be that we live in a universe (potentially filled with life) that can't ever be visited by any member of that universe just due to the laws of physics of that universe.

If travel at some fraction of the speed of light is an absolute limit and if the closest star/planet is too far away for us to ever reach it then whether the universe has abundant life or not is almost a moot point if we can never observe it.

Thanks for the post!
More people should read it to understand we are a very small part of the universe.

What a exciting time are we living!!

Looking at it statistically there has to be life on more than just the Earth. Think about it, the elements we're made from are common throughout the galaxy! We are after all star dust.

And it can't be just our little G2V star that has life circling around it.

Very nice summary.
I did not know a lot of the things you explained and put in perspective.
Thanks.

Fascinating "mind opener". Thank you dear Ethan.

Wonderful post. Thank you.

For a while, I have been wanting to get some sort of visualization tool for the #'s of "things" in the universe. I was thinking of the # of grains of sand on a beach compared to the # stars, galaxies, etc. Your post today was a prod to do it.
Assume - beach 30 meters wide, 1 meter deep. Sand - 8 grains/cubic MM (http://www.6footsix.com/my_weblog/how-many-grains-of-sand-i.html)

So, with a little rithmetic, we can get the length of a beach corresponding to these things:
1) number of galaxies - 0.83 meters. - OK, I can visualize that, and it is a lot
2) Number of stars in our galaxy - 1.66 meters.
3) number of stars in the observable universe - the beach would be 333,333,333 Km long. (207,100,000 miles for those of us mired in the English system) Now things are getting out of hand
4)(gulp) # of planets in the universe. - the beach would be 4,166,666,667 Km (2,588,750,000) miles long. This is pretty close to the distance to neptune.
Well, that was interesting, at least to me.

Until recently I had imagined that the stellar wobble method for finding exoplanets would involve measuring the visible change in a star's position as viewed from the earth, for example right-to-left and back again. I learned just last week in the book store that this isn't the case, though, and that you can get much more accurate measurements from the redshift and blueshift of the star's light as it moves in the plane towards us and away from us.

This made me think that just as the transit method requires a system be edge-on to us, the Doppler method would require that a system not be oriented so that we view it directly, or almost directly, from above or below--since this would mean the star didn't move, or hardly moved, in a Doppler-detectable direction.

So: how big would this blind zone of star system orientations be, what percentage of systems would we expect to fall into it, and is it a factor in counting/estimating the number of planets?

I don't think anything has ever fired up my imagination the way the search for exoplanets does! I would quite happily die tomorrow if I could spend the time until then poring over a photo album of gorgeous, strange scenes from other planets in our galaxy.

There's a transverse effect to the dopler shift.

Smaller. But there.

Huh, so I wonder how you tell the difference between a small Doppler effect that's due to a large planet in a "bird's eye" system, versus the same small effect that's due to a (relatively) small planet in an edge-on system... can we tell which plane a sun-sized star is spinning in?

So , using doppler shift, if we are looking directly in the plane of the solar system, we will see a particular red shift. If we are at 90 degrees, we should see no redshift (I see above the transverse red shift, but I don' understand this, so I am ignoring it - Call it poetic license.
Now in the intermediate case, say 45 degrees, the redshift will be present, but half of what you would expect in the edge on case.
Now - here is my question - since the degree of redshift depends on the angle at which we view it, how is it possible to correct for this when trying to calculate the mass of the planet?
Also, in the pure situation of one large planet, the redshift method is clear, but let's say there are 4 large planets. The redshift will be a very complex curve. How does one compute the number and mass of each planet.

(i'm waiting for the answers here to start work on the data I gathered last night ;)

Phil as I understand it when there are more planets you have to decompose the complex curve into its constituent parts, much as you decompose a soundwave into its constituent (pure sinusoidal) partials, by e.g. Fourier transform.

You had the same question as me above about decoupling the mass effect from the angle effect, but it's not a problem if we can detect how the star is rotating--then we know how much to correct by. And it seems, after a little more searching online, that there are methods for finding a star's rotational velocity and direction. At least, I've seen it's possible for some stars though I haven't yet seen explicit confirmation that it's possible for sun-like stars.

Oh and it's not hard to imagine the small Doppler shift in a system seen from above: a pure sideways motion, as seen from earth, will mean the star is very slightly further away at the endpoints of its lateral motion. Imagine a very long equilateral triangle with the earth at the skinny part and the other two corners the extreme points of the star's apparent excursion. When the star is at the center of its motion, forming a right-angled triangle with the earth and either extreme, a little trigonometry will give the difference in length between the two long sides.

sorry, I meant isoceles triangle, not equilateral, of course.

Even if only 0.000001% of 150 billion have life on them, that's still 15000 planets with life in our milky way! And if only 1% of those have intelligent life, that's 1500 planets with different races.. amazing :) Starfleet here we come ;)

sorry... last number should be 150 not 1500

even at 1500 planets, that makes an average distance between them of around 6000 light years between each system.

To be honest, that's why sci fi ALWAYS has FTL travel. The reality, without FTL travel, is that you leave one planet to colonise another and never heard from again.

Even if you were a creature living 10 million years, you wouldn't bother with a conversation that took 12,000 years for each message/response.

I've concluded, as GB seems to say, that in spite of all the intelligent life there likely is, we'll never meet. The distances are too great. Contrary to GB saying "filled with life", the galaxy is an immensely huge void with tiny specks of life scattered very far apart.

Dr Rod, the galaxy might be mind-bogglingly huge, but it's also mind-bogglingly old - so old that there could be (and I'd bet there are) civilizations* out there that watched their home star burn out before ours even formed. They've had more than enough time to fully explore the galaxy.

They'll also be technologically immortal, so it doesn't have to be restricted to von Neumann self-replicating space probes either (which could do the job, travelling no quicker than 0.1c, in just half a million years: http://www.rfreitas.com/Astro/ComparisonReproNov1980.htm )

*unless it's just the one... First civ to get out there basically claims the lot. Civs 2+ will be so far behind (odds of similar tech levels meeting are tiny), that the oldest will be galaxy-spanning before the second one gets off its planet.

@uncleMonty: The "radial velocity method" (those are the right Google keywords) uses the main Doppler shift, not the transverse. The magnitude of the shift (often translated into velocity) is fit to a Keplerican (orbital) oscillation with the planet's mass and the orbital inclination both unknown.

The result gives you the planet's mass in the form "M sin i", where sin(i) is the sine of the inclination angle: 0 degrees is edge on, and 90 degrees is face on.

The fit is more complicated with a multiple-planet system, but you can do it where the "sin i" is common to all terms. That may not be strictly true (it isn't exact for our Solar System), but it's close enough to get decent fits, as well as to rule out spurious signals (like stellar oscillations).

As Ethan wrote, the transit system is limited to essentially edge-on systems (sin i ~ 1). When you can apply both methods to the same star, you can derive "exact" masses for the planets.

Ethan, based on these numbers, what would be the latest value (estimate) of the Drake equation?

In response to Phil S. about visualization...

I once had a book called "One Million". It consisted of one million dots printed several thousand to a page. Every once in a while, a dot was singled out with an annotation: "Number of Hindus in Brazil", "Telephones in China", "Days since the founding of Rome", and at the end of the book "Number of dots in this book".

Using grains of sand (or anything on the mm^3 scale) to visualize "billions" is pretty nice. If you took that stretch of beach that corresponds to the number of stars in the Milky Way galaxy and scattered the sand into a scale model of the galaxy, with the average grain (0.5 mm diameter) corresponding to the Sun's diameter (1.4e9 m), the model of the galaxy (1.1e5 ly, or 1.04e21 m) would extend about 7.4e11 sand grains, or 370,000 km -- roughly the distance from the Earth to the Moon.

One point we all seem to be missing is the huge uncertainty in one element of the drake equation (an equation that lays out the factors that multiplied together determine the probable number of detectable extraterrestrial civilisations out there). The really big unkown is fl - the fraction of potentially habitable planets that go on to develop life. We simply have no idea what this number should be. It could be close to unity, or on the other hand it could sit at the ten to the power minus 100 and above level. We don't know because we are still pretty much in the dark about how the first life evolved on our planet. Until we have a good understanding of that we will simply be guessing wildly at this key number. And it makes a huge difference - put in 10 to the minus 100 and even with Ethan's 10 to the 24 planets the probablitiy of life out there is essentially zero. We must simply admit that based on planet numbers etc at this moment we have no idea if there is likely to be life out there.

Heck the surface of the earth can be described as that wrt people.

Just imagine if there were no telegraph and no transport beyond legs or swimming.

GB:

Don't despair! Actually, the laws of physics does allow to reach many of the surrounding worlds, even to the point, that there's the theoretical possibility to coast around a good bit of the observable universe. It's all in the laws of relativity.

First of all, the only theoretical speed limit we're aware of is that of the speed of light. While there's a lot of reason why we can't reach even fraction of that speed today in respect to the rest of the universe, none of us can really predict what we will be capable of doing within let say 200 years. We certainly have come a long way since 1813 the steam locomotive was only spanking new invention just about the change our idea of mass transport. We already have theoretical design for interstellar spacecraft, and the most likely design that would eventually enable to travel interstellar distances in human life time is going to be something similar to the Bussard ramjet (http://www.askmar.com/Robert%20Bussard/Catalytic%20Nuclear%20Ramjet.pdf).

In short the idea is to provide constant acceleration by the help of the interstellar medium. While the interstellar medium is scarce, as the spacecraft gains relativistic speed, the collection rate would increase.

With relativistic speed (in respect to the rest of the material universe) one will encounter with time dilation which in turn would resolve the problem of reaching vast distances within reasonable time. When you reach around the 88% of the speed of light, you'll start experience serious time dilation (that's where it reaches around the factor 2). As you get closer and closer to the speed of light of course, the time dilation will cut you off from the human race on earth or even in the solar system because the time dilation gets so high that perhaps no one will be alive by the time you decelerate and come to rest in respect to you destination star system.

@Michael: you wrote "@uncleMonty: The “radial velocity method” (those are the right Google keywords) uses the main Doppler shift, not the transverse."
Thanks, that's what I believed in the usual cases but I wondered how it worked for a system whose star we view from one of its poles. In that case there is a tiny Doppler effect, since as the star appears to wiggle from side to side it must also change its distance from us (I think this is what Wow meant), but my back-of-the-envelope makes the effect much too small to do the job. Is that right?

It's too bad that the same systems that are best suited for Doppler methods are also the ones most likely to involve transits.

Ethan,
Have you ever come across someone's knowledgeable power spectrum estimate of masses in our galaxy, from blue giant to brown dwarf to super-Jupiter to dwarf planet?

And, thanks again for yet another informative piece,
-Bernie

@ Mark McAndrew:

It does no good for a meet-and-greet with alien lifeforms if they already passed through our neck of the galactic woods hundreds of millions of years ago. The age of the universe cuts both ways -- yes it's more than old enough for a hypothetical alien civilization to have explored all of the galaxy, but that doesn't make it any more likely that they'll be right here during the incredibly brief moment we've been around and able to notice and record the fact.

Cool piece. How about a write up on hot jupiters!

@Progician

"Don’t despair! Actually, the laws of physics does allow to reach many of the surrounding worlds, even to the point, that there’s the theoretical possibility to coast around a good bit of the observable universe."

while you are correct that laws of physics allow, the rest is just bollocks. Just because something is allowed by current laws doesn't mean it's either practical or doable. There is nothing in the laws that prevents i.e. humans evolving wings and flying. There is nothing in the laws that prevents us from building a spaceship powered by a black hole or bad news for that matter. That still doesn't make it real or feasible. And the paper linked is just someone's daydream... Besides, interstellar space is a much greater vacuum than what we have on earth. To "extract" hydrogen from such a vacuum is a joke, even the author realizes it doesn't work so he put's in some nebula in there.... And he somehow fails to address where does the energy for fusion come from.. what powers the ship before it starts "vacuuming" the interstellar hydrogen? All in all.. bullocks.

p.s. while thinking more on the subject of hydrogen powered fusion reactor.
It would be much more logical for it to be powered by astronaut piss than interstellar hydrogen. Much more hydrogen atoms in one cup of piss than any that can be scooped up by a ship from the vacuum of space. Wonder why the author didn't think of that.... rofl.

A read mind bender. Funny how we enjoy the universe from our stationary planet named earth.

Plug this into the Drake equation, and all you can get so far is that the answer might still possibly be non-zero. With so many planets out there, the odds pretty good that at least some of them are hospitable at least for extremophile bacteria or things like those. The three really big unknowns, though are still:1) getting life (of any type) started on a planet in the first place; 2) getting something like a Cambrian explosion; and 3) making the leap to self-aware intelligence. The combination of these three contingencies might be so rare as to still assure that we are alone.

WRONG YOU SO CALLED SCIENTISTS WILL BURN IN ALL ETERNITY FOR TORMENTS BECAUSE THERE IS ONLY ONE PLANET EARTH WITH PEOPLE THAT OUR LORD AND SAVIOR JESUS CHRIST LIVED ON AND TO SAVE THE SOULS OF HUMANKINDS HE GAVE HIS LIFE AND ALL THIS TALK OF PLANETS IS NOT IN THE BIBLE AND TRUELY IS FROM THE DEVIL HIMSELF TO BLIND AND DECIEVE THE GOOD PEOPLES OF CHRIST

There are as many planets, galaxies, stars, as the power of a telescope can see. I believe that if our telescopes could see infinitely far, we'd see infinitely more celestial bodies out there. Its absurd to try to estimate the that number when we have no idea how big the universe is. We could be seeing only a small portion of it, or it could infinitely big.

Thank you Ethan for another outstanding article!
I would be very curious to hear your ideas about Andrei Lebed's theory presented here: http://www.dailygalaxy.com/my_weblog/2013/01/-einsteins-emc2-may-breakd…

knightEknight,

I have a longstanding policy (for about four years) of not plucking a bad science article from obscurity to tear into it and talk about the problems with it.

So it's unlikely I'll be sharing my ideas about Lebed's theory; better to leave it alone and let it languish in obscurity where it belongs.

Thank you! That is actually very helpful! :)

Amazing post! Where do you get all the amazing pictures for your post? You always have the best pictures, and I always end up changing my desktop background when I read this blog.

I haven't read all the comments, but a common opinion I see is that even if there is life out there, the distances are too great, and we will "never" be able to reach them. I'm currently reading a book (The Stardust Revolution, which I highly recommend) and in the first few chapters, one person, I forget exactly who, in the 17th or 18th century was certain, absolutely certain, that we would "never" be able to know the composition and chemical make-up of the stars. They're simply too far away. It was less then a century later that spectrography was invented. So, while I won't tell anyone that faster than light travel is certainly possible, I will absolutely keep an open mind, and not underestimate the scientists of the future! Especially looking at how incredibly fast our technology is advancing, and the new doors to the universe it is opening up.

" that we would “never” be able to know the composition and chemical make-up of the stars."

And they were right.

We had to get spectroscopy before that could happen, since it's far too far to walk, and we'd die from heat stroke if we tried.

"I will absolutely keep an open mind"

You seem to be preening yourself on this.

However, Captain Obvious, nobody is closing their mind to it. Hell, I'll quote you one that you probably never really read, just read the words you thought would be there:

"The reality, without FTL travel, is that you leave one planet to colonise another and never heard from again."

So even if you want to insist FTL WILL happen, without it, you leave one planet to colonise another and never hear from again.

gotta be '100-to-200 billion stars not planets in the Milky Way'

Presumably, the stellar wobble technique suffers from higher false negative rates, the more planets there are orbiting a given star. It seems intuitive that the more planets there are, randomly positioned (ie not all pulling in the same direction), the closer the system's centre of mass will be to the centre of the star. Has this been analyzed?

Thank You.

My journey in spirit brings me to the matter that makes up the Universe and the lessons in written word and physical solutions and equations that join me in the matter bring me to this place and space in journey.
So.....that being stated....without knowing Math or Science as well as the books teach.....I would like to just hear thoughts on the hypothesis that as we continue to evolve in this time and space , we can know the past and see the future. Eventually , we will be not only genetically altered and modified but our advancements with travel will advance to use a method that can travel dimensionally.....to the past universes in which our present selves occupy....and at this time in space.....our life may be altered so much so, as will our universe and planet....we will need to travel back to acquire the only minerals that we would now use for energy and food....(this future may not have agriculture from what we have done to it and the bodies could be technically and so genetically altered .....our food could consist on the same minerals that furl our energy. So ....if we can indeed see the future.....out there....but we can not yet travel to it......Don't you think the future life(whatever it may be) would maybe even want to warn us of the godless hell we are allowing to take shape??! Symbols, messages, equations, letters, creation and the lessons are everywhere.....it is our CHOICE to see and use for selfless , Love , positive energy to create and live.....for positive spirits to rise...... we KNOW THE FUTURE.....and it is almost here.....FAITH has continued to prove itself......without my asking.

“Ridicule is the only weapon which can be used against unintelligible propositions. Ideas must be distinct before reason can act upon them; and no man ever had a distinct idea of the trinity. It is the mere Abracadabra of the mountebanks calling themselves the priests of Jesus.”

― Thomas Jefferson

wow grabe its so wonderful i kant explane mt happiness when i see those pictures that was really awesome god is really braive because hi did that

Awesome!!! That's all I can say. God is great for all He works...

Would it be acceptable to come along to your church and in the sermon start pointing out all the fallacies in the bible?

Really, what you godbotherers are doing is EXTREMELY rude.

Some random thoughts..

As far as bacterial/simple life goes, I would expect it to be widespread. The logic runs this way:

- Life appears in the geological record on Earth basically instantly - the moment it's possible to detect life in rocks, we see it. If life appeared as an extreme-low-probability event there would be no reason to expect this.
- The idea of life emerging as a result of random chemical interactions is essentially impossible. Additionally, there is no conceivable stable state which is a 'half-way house' between simple inorganics and life. You cannot, for example, postulate complex-but-not-self-replicating RNA hanging around for millions of years. Not in liquid water.
- Hence I would postulate that life emerges quickly - probably in a pretty energetic environment such as a black smoker - when conditions are correct. If so, that would imply that simple life would emerge virtually everywhere.

However, I'd also observe that for at least 60% of the history of our planet, it was microbes-only. There are good reasons for this - the lack of free oxygen being a major one. And this will probably hold more generally - the complexity of life will be limited by the complexity of the environment and the available energy flow. Earth, for example, has an extremely varied and complex environment, and the availability of oxygen and sunlight mean that there is a high energy flow. Whereas life under an icecap will have little diversity of environment and low energy flows; it may stay stuck at bacteria forever.

As far as intelligent life goes.. it could be argued that it's been possible ever since the mammal-like reptiles emerged >200 million years ago. So these could really be the rate-limiting steps to the Drake equation - changing the redox state of the planet to allow oxygen, followed by the dumb-intelligent transition.

An interesting observation is that around a red dwarf star, the first of those steps could quite possibly take 10s of billions of years. On the other hand, around a star hotter than the sun, it may be faster, but not fast enough before the star went bang. So we could be amongst the first.. and the 'golden age' of civilizations emerging from red dwarfs in their thousands lies many billions of years in the future..

- Life appears in the geological record on Earth basically instantly

Well, within a few million years, which is about as close to instant as the resolution of dating methods to that age get.

- The idea of life emerging as a result of random chemical interactions is essentially impossible.

That means you think life itself is essentially impossible. Something has to live to create something, but something can't live unless it's had a creator, is what you're saying. But that creator is essentially impossible since it had to emerge as a result of random acts itself.

Additionally, there is no conceivable stable state which is a ‘half-way house’ between simple inorganics and life.

RNA.

And, since our definition of "organic" is "carbon based", any carbon-active catalyst is a half-way house between the two.

E.g. clays.

You cannot, for example, postulate complex-but-not-self-replicating RNA hanging around for millions of years. Not in liquid water.

RNA do replicate, though.

Your assertions seem based entirely on your incapability at biology. This is possible to rectify if you wish to. However, most "Creation MUST happen!" acolytes don't wish to.

Wow - I'm not a creationist ( or panspermia advocate). Would you like to reconsider your reply?

Yeah, and Stalin wasn't a despot. He said so.

Would you like to reconsider your assertion I replied to?

How many planets are there

Several.

Ok, late reply. Although if any statement I make is automatically a lie if it tries to make you think it could be tricky.

The concept of an ocean full of complex organics giving rise to higher complexity is something I am arguing against, on extremely firm grounds - even the highest reasonable estimates of concentrations give a situation where hydrolysis rates would exceed any replication rate by many orders of magnitude.

Indeed, such arguments also rule out any notion of the 'long middle ground' of life formation. Which is good news for both astrobiology and any hope of replicating abiogenesis in the lab; there is simply no chance that a 'complex but nonliving soup' could persist for a noticeable amount of time, geologically speaking, so not only must abiogenesis be fast (again, geologically speaking) but it must follow a fairly set pathway.

The best hypotheses I've seen thus far revolve around the conditions at hydrothermal vents, which contain things like redox gradients, Fe-S complexes and clay minerals to promote mono-isomerism. Yet these environments persist for perhaps 10,000 years or less. Interestingly, any planet with substantial oceans on a silicate crust, even under an ice layer, will have 'black smokers' at some point.

So - unless the mechanism for abiogenesis relies on a very Earth-specific process (which I haven't even seen suggested) - then the chances are that it is both fast and near-ubiquitous.

@Andrew
"Yet these environments persist for perhaps 10,000 years or less."

why is it so hard to do some research before posting data?

from wiki: Strontium, carbon, and oxygen isotope data and radiocarbon ages document at least 30,000 years of hydrothermal activity driven by serpentinization reactions at Lost City, making the Lost City older than known black smoker vents by at least two orders of magnitude

"even the highest reasonable estimates of concentrations give a situation where hydrolysis rates would exceed any replication rate by many orders of magnitude."

Which is why the complexity was probably on the shores, not the deep ocean.

Please, stop arguing against strawmen, it's tiresome.

So what is your alternative theory? That some god-like-but-not-god-honest being waved their magic^Wscience wand and created^Wdesigned life on earth?

Sinisa -

I was going from memory. Say < 100k years. On geological timescales, near-instant..

Wow -

Calm down. As I said, I lean towards the black-smoker hypothesis (The idea of tidal pools is interesting, but you have to ask where the chemical gradients are in such a scenario).

My actual argument is this:
- The early appearance of life on earth points to rapid abiogenesis.
- It's also reasonable to argue from a chemical perspective that the process is rapid. Slow processes are actually harder to envisage.
- Therefore one should expect microbial life to be extremely abundant, assuming that the process operating on Earth was not a freak one.

I don't think that this is controversial. I would use it to predict life on Europa, IF Europa has a genuinely liquid water ocean in contact with a silicate mantle. Mars as well.. at least at some point in the past.

My actual argument is this:....$LIST

Then your opening statement was a complete waste of EVERYONE'S time.

- The idea of life emerging as a result of random chemical interactions is essentially impossible.

Is what you had as your bullet point in your opener.

Seems your argument as you are willing to say now never included that statement. If your actual argument was NEVER "the idea of life emerging as a result of random chemical interactions is essentially impossible.", then why the hell did you say it?

Just trolling?

actually.. the sentence "- The idea of life emerging as a result of random chemical interactions is essentially impossible." and " The early appearance of life on earth points to rapid abiogenesis" are totally opposite.

Which is why it might have been entirely troll.

Or it could be some IDer who found they weren't going to get any traction and have backed down and changed everything so they can then complain they've been done so bad by those mean religious scientistics.

So there are mega billions of planets that "could" support life (ie in a habitable zone). Do we have any way of telling which ones actually do have life. No. Or even what likely % of planets within habitable zones have life. No. So considering how far planets are from each other what are the odds that we will ever make contact with another living world ?? If we have to actually visit a planet to confirm there is life on it (and that may be necessary coz not all aliens will answer the phone if ye know what i mean) then this would be a project like no other, hopping from planet to planet, breeding & training generations of explorers on the way. Makes ye kind of wonder did some planet do this millions of years ago and they wound up here. heeheehee

There are possibilities.

For example, our atmosphere is VASTLY over specced on Oxygen. This amount of O2 in an atmosphere shows that there are processes like life on here keeping the atmosphere this out of balance.

Make as many comments about Universe and Planets as you could but, please, never inset the idea of "Lord" or "God" in this theme, it's very absurd and idiot. I hate very much someone - the Christians the most parts - use to impose their belief on the existence of their Lord or God in this discussion .

life is possible on other planet?and how many planets are currently discoverd? Tell me soon..

The religious get cheesed off (as a group, not necessarily as individuals) when atheists bring up "There is no god" in a discussion of the existence of god or where they are talking about it for any reason, so quite why they think it's fine to talk about there BEING a god when nobody is talking about it really eludes me, unless it's that A Crowley idea of "Do as thou wilt is the whole of the law".

But then they're sharing several other traits with Satanists then.

Very studious

I love these articles that summarize just how inconceivably huge the universe is.

You guys going off about which chemicals mixed to create life, how, and how long it took are all trolls. This article is estimating how many planets there are. Bugger off to your evolution forums. :)

I never knew that pluto has gone to rest because is to small. Well u are doing a great job.

That's totally mind boggling. I wonder why God would want to make so many planets.

One million trillion planets is not a lot to Him, since He is infinite in power, presence, wisdom, wealth, and knowledge.

hey friends i want to be a astronomer i will build a building to discover all the ten trillion planets in the universe see that is impossible but with god all is impossible

A wonderful demonstration of the effect of psychedelics on the human brain there...

how many days does it take to get to planet & can u find emty land there?

Planets or no planets God owns our lifes.keep searching

i like the way you present

Please u Christian guys respect the man's proffesion n work his doing,it's not the place to argue with people who do not believe in the Lord Jesus Christ.Please don't impose your God or Biblical knowledge Ethan i believe altough not really understanding what he say, gives scienctific and mathemetical explation of how vast the universe is.Please stay with the subject and give the man his due.as for people who does not believe or see as we Christians i humbly apologise 4 my fellow Christian brothers or sisters if there is any.But in as far as life out there is concern i firmly believe they are there, they are however not as us, under free moral agency.YES U HEARD ME RIGHT THERE IS LIFE OUT THERE BUT NOT UNDER FREE MORAL AGENCY.IT MAY SOUND UNBELIVABLE BUT THE SOURCE IS NOT SCIENCTIST,IT SOUND CONTROVESIAL BUT I WISH TO AVOID ANY DEBATES PLEASE

I never see like that . very wonderful for me .

if we can discover more than the speed of ligth there is a posibility that we can reach/go to the neareast star. this is a challenge to us to change einstien said that nothing can exceed the speed of light. discover more fastest rockets.

The numbers in the article are pure speculation. Physics indicates that massive stars could have several thousand planets.
Anyways, if life is rare as in only being found on quintillions of planets....intelligent life ever rarer and only on quadrillions...way too dispersed for much hope of us ever having any evidence of intelligent life 'out there'.

Re a comment on the Universe being 'old'. Actually it is still in its infancy. Regardless of what the fate of the Universe is, the scenarios play out over trillions of years. We're still in the first 1% of the Universe's existence.

i comment that it is possible to live in the new planet like mars or the new one discover above our planets 400000 light years away

Wow! I impress with this

The creation of the universe is explained by astrophysicists as a widely accepted phenomenon,
Popularly known as "The Big Bang", According to the "The Big Bang" the whole universe was initially one big mass (Primary Nebula) then there was a "Big Bang" (Secondary Separation) which resulted in the formation of Galaxies, then divided to form stars, planets, the sun, the moon etc.
HOW COULD A BOOK ( THE QURAN ) WHICH FIRST APPEARED IN THE DESERT OF ARABIA 1400 YEARS AGO, CONTAIN THIS PROFOUND SCIENTIFIC TRUTH ?

I would like to volunteer for the type of job Jodie Foster had in "Contact"... I don't mean the high-tech stuff; but the sitting on the top of a hill, with headphones on, listening to outer space. My kind of job!

Einstein's theory of relativity insinuates that nothing can move faster than the speed of light. This has recently been proved wrong and has been holding scientists back for years. Neutrinos have been proven to travel faster than light speed, therefore one of the most fundamental hypothesis of early science have been proven wrong.

@Cruiser: I'm so sorry that you're as far out of the loop as you seem to be. What was proven, more than a year ago, was that the precision timing circuit used by OPERA had a systematic bias due to an improperly plugged in fiber-optic cable, leading to an approximately 70-ns offset in their time-of-flight measurement for neutrinos from CERN to Gran Sasso.

If you're going to make wild claims about the overthrow of physics, you really ought to try to know the details of the work that led to that overthrow (or not). Otherwise, you end up appearing to be just another crackpot.

Well, the cable was loose and it was fixed under "any other business" but never actually proven to be the cause, it's just that the change COULD have produced that error in timing and that they've not been able to recreate it since then. The uncertainty is that they couldn't tell if it was done as the cable got fitted better or some other reason.

It's feasible and FTL is a bit of an amazing claim.

IMO they were right to push the note out there because a lot of people tried several ways of thinking

a) How could it be wrong (nobody figured a loose cable)
b) What would it men if it were valid

and it probably got a few more people interested in thinking about it that weren't really "into" physics any more. That some are kooks is merely a reflection of humanity.

@Wow #93: Almost. As I recall, what happened was that CERN did a short-pulse run (where OPERA could get spill-by-spill timing, rather than averages), and they saw the same offset. After discovering and fixing the cable, they had more short-pulse data where the offset went away. This was described in the updated version of their September 2012 preprint. I think that the before-vs-after effect is fairly conclusive.

Well, I never got to see a preprint of anything. The misalignment would have to be very small to create a capacitance of that size and the fittings are pretty much designed that it's pretty damn secure (this one was considered to be a knock that unsettled it). What I had heard was that they found a possibly loose connector and fixed that, then found it no longer gave the discrepancy. But maybe they'd done some testing to find that loose connector to know out of the probably ten million cables which were not acting to spec.

PS the "unclarity" was more along the lines of "we can't PROVE it, but it is both suitable and sufficient" allied with "and we can't get it to do that any more".

Which is good enough proof to get people sent to prison for capital crimes.

@ Wow

here is the final paper

http://arxiv.org/pdf/1109.4897,

(the one everyone agreed to sign :) )

Ta very much.

Now if only my document viewer didn't decide to open it up with a default 32 point font...

OK, looks like the delay is dispersive medium rather than capacitive. That makes it a big easier to get a 70ns delay with a wonky connector.

Also appears thermal wobble changing the trigger level had a place to increase error bars.

I read quick. :-)

@Wow: Just saw all these replies :-) Thanks to Sinisa for the link back to arXiv! Yes, that's the paper, and I'll tell you that I shared your initial confusion about how a "loose connector" could cause a delay. I had to talk to some optoelectronics experts at my work to really understand it.

On a side note, Wow, congratulations.

Your comment #99 on this thread makes an even 4,000 comments for you. Although there are more than 30k approved comments, you are by far the most prolific commenter on my blog, and I wanted to congratulate you on your milestone.

I knew as soon as I heard the results that every crackpot on earth would glom onto the OPERA neutrino result and never let go. They'd assume that the preliminary result was the bonified truth, and never bother checking on it again (whereas I *wanted* it to be true, yet also wanted to know if it *really* was, so I payed attention to the ensuing investigation).

Hell, I still hear people using the Pioneer Anomaly as "proof" that all of modern physics is wrong.

Why would you check on the latest news when you already have your proof? The only difference it could make is that you find out you're wrong.

You spelt that right, yes, Ethan?

It wasn't "Millstone"? :-)

hehe... Happy Post Day Wow :)

It wonders me how the universe works because it's seintificly proven that we are not alone people don't realize how many different species there are in the the galaxy + there are over 50000 different planets

Never underestimate the universe with its powers

this shows that we humans are in a small part of the universe and also the superior of all creations by GOD. We have made researches on the planets outside ours why cant they(other planets) make some research about us?

That's a lot to take in

IF SPACE IS INFINITE, WILL WE EVER DISCOVER HOW MANY PLANETS THERE ARE? AND WHERE DOES GOD AND RELIGION FIT INTO THE SCHEME OF THINGS?

No, by definition, if it's infinite, we will never find out how many planets there are.

God doesn't fit anywhere in it.

And religion is not part of it any more than political affiliation is. It's something some humans decide to engage in, others self-identify with but otherwise do not engage in, and others ignore.

"WHERE DOES GOD AND RELIGION FIT INTO THE SCHEME OF THINGS"

Brian, you use of capitals makes it uncertain as to whether you meant God or god, but your choice of the singular suggests the former. You may not be aware but there are thousands of postulated gods. Depending on how different sects may be before the become a different religion, there are even more religions. Whatever all or any of them may have done in the past, they are now largely constrained to a bit of minor tinkering in areas where Science can't yet look.

Brian,

God fits nowhere into the scheme of things because the Christian concept of god is inherently non-scientific. To fit god into the scheme of scientific observation, you must find a way to put god's existence to the test. That is, you must find some observable part of the universe that would be expected to look different depending on whether god exists or not. If you actually make the observation, and the results indicate that god actually does not exist, you must be then willing to admit that god doesn't really exist. I suspect that you, and most Christians are either unwilling or incapable of doing this.

PS. I am assuming that you are coming from a Christian perspective here. I apologize if that's not the case, but my points pretty much hold up for any concept of god, not just the Christian one.

I strongly believe that earth is the only planet in the universe where such a wide range of life forms exists.

good info

Beyond, beyond and beyond is what amazes me. There is no walls to the universe or outer space. If there were walls, what would be on the other side of those walls? Therefore, there is eternal time, unlimited space and numbers. This is a mystery.

hmn, wat a wonderful world

OMG. I Honestly Thought it would be written out like this, considering our universe never ends...
100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
And Also You Think That Earth Is The ONLY Planet in the universe that has life!? Give me a break.

Also It is inpossible to know how many. If you took everybody's brain in the world (smartwise) and put it together it would not be able to get even the exact amount of inches of land in the world.

the universe is never ending
it cant explode
it cant just disappear
it will stay here forever

i want more information about this topic

There's an entire internet out there with indexing of its contents available for you to use.

If you wish someone else to do the work of collating and explaining it, then there is a vibrant adult education system you can apply to use.

What are the two things that are faster than the speed of light?

The creation of the heavens and earth is greater than the creation of mankind, but most of the people do not know.

Of course we have no idea how many planets we have in our solar system. I was just wondering if anyone would be dumb enough to put 13 (Our main eight plants and our 5 dwarfs)

i'm an amateur astronomer and i know the 10 to the 24th power is in fact 1 septillion and since i do understand large #'s our known universe is approximately 15 billion light years which translates to around 90 septillion miles.

i also know that it won't be in my lifetime which i hope is another 25-30 more years that man will be able to fly the speed of light. it's called einsteins theory of relativity in which the close you go towards the speed of light the slower time gets,

this theory has actually been proven experimentally, it's called time dilation. i believe star trek calls it warp drive.

" La scienza non deve aprire una porta al sapere ma chiuderne una all' ignoranza."

" Science doesn't have to open knowledge's door, but close ignorance's one. "
-Galileo Galilei

The answer is 42.

Yes, Mick, but what's the question? :)

i need to know more about planet and how have bee discovered, with there picture

@CHICHI #130: In English, https://en.wikipedia.org/wiki/Exoplanet. I don't know whether Wikipedia is available in any of the local languages of Nigeria.

Fantastic topic and amazing to see a truley global debate taking place. I only hope that future exploration of what is potentially "out there" and how to get to it will only further unify what we have "on here " and how we make the most of it.

It is funny that the estimated number of planets in the observable universe is close to one mole (Avogadros constant)

Less than imagine

good evening, so can one live on the other planets and how does it benefit man and in what way does people find their way to the planet , if i may ask what sort of things can be find there and is it true that the planet is only nine and why do they say that .

Wow great photo's....... the univers of all human and substance particle depend in gravitational force.

You know the largest crater on the moon is the South Pole - Aitken Basin . it is 2,240 km in diameter and 13 km in depth . my Aim is Scientists of Paleontologists .

in the other planet in other solar system . . there's a posibility that there are other people or living things or anyone who are breathing Living in other planet on the other solar system ?

how many planets in the universe

I have a question: Isn,t it possible that smaller than the smallest stars form a without light mass by gases as the stars formed ,if so there shoud be milliards of without light huge masses that may give an answer to the weight and noise of the whole universe .

The number of planets that exist is infinity.. If infinity is defined we can say it is equal to number of planets in the universe.

awesome article

The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy.

Original estimates
There is considerable disagreement on the values of these parameters, but the 'educated guesses' used by Drake and his colleagues in 1961 were:

-R* = 1/year (1 star formed per year, on the average over the life of the galaxy; this was regarded as conservative)

-fp = 0.2-0.5 (one fifth to one half of all stars formed will have planets)

-ne = 1-5 (stars with planets will have between 1 and 5 planets capable of developing life)

-fl = 1 (100% of these planets will develop life)

-fi = 1 (100% of which will develop intelligent life)

-fc = 0.1-0.2 (10-20% of which will be able to communicate)

-L = 1000-100,000,000 years (which will last somewhere between 1000 and 100,000,000 years)

Inserting the above minimum numbers into the equation gives a minimum N of 20. Inserting the maximum numbers gives a maximum of 50,000,000. Drake states that given the uncertainties, the original meeting concluded that N ≈ L, and there were probably between 1000 and 100,000,000 civilizations in the Milky Way galaxy.

WOAH! So I decides to google... "How many stars are there in the universe?
Answer:
"To answer “how many stars are there,” we must limit the discussion to what we can observe. Astronomers estimate that the observable universe has more than 100 billion galaxies. Our own Milky Way is home to around 300 billion stars, but it's not representative of galaxies in general."

So I said screw you google. Ill make my own rules! By generalizing the Milky Way Galaxy civilizations and multiply that by 100 billion galaxies, so I could get a rough guess on how much intelligent life, could possibly be out there. (Correct me if I did this wrong)

So 50,000,000 civilizations X 100,000,000,000 Galaxies in the universe X 300,000,000,000 Stars in the milky way (as a general guideline) = Rough Estimation of intelligent life in the universe.

The conclusion,

1,500,000,000,000,000,000,000,000,000,000

Usjebxudiwowndhuxd7hej3so blaaaaaaah!

Thats 1.5 Nonillion (30 Zeros) of intelligent civilizations. The real number could be double, or less than half.

Either way, weather you believe it or not, life exists outside of our mother earth. And very abundantly.

Now after reading this article (ive copied and pasted my formula) that NOW, that number could be quadrupled) I even heard there could be as much as 500 billion galaxies

"Either way, weather you believe it or not, life exists outside of our mother earth. And very abundantly."

I disagree. We can estimate how many planets are in the universe, but we have really no idea of really knowing the probability that complex life - let alone intelligent life - evolves on any of them.

Drake equation is nothing but guesstimates.

10 with 24 zeroes isn't all that many, actually. Think about It that way: you keep on dividing it by 100, you only need to do this 12 times to get down to 1. In other words, if a planet has to meet only 12 criteria to allow life, and there's a 1% chance of meeting each of this criteria, then it's quite likely Earth could be the only winning ticket in the universe.

And there's plenty of factors. If we had no Moon (that helped to stir the primordial soup with its tidal influences), or if there was no Jupiter and other gas giants (they shield us from collisions with objects entering the Solar System by intercepting them), or if Earth's axial tilt wasn't mere 23 angles but more (meaning we wouldn't have mild seasonal climate transitions), or if the orbit wasn't stable, or...

And even on Earth, evolution had to be "rebooted" several times (five mass extinctions, dinosaurs weren't even the biggest one) before intelligent organisms happened to evolve.

And even on Earth, evolution had to be “rebooted” several times

Which was done by primitive organisms, WHICH ARE STILL LIFE.

Again, the difference between life as biology and life as we parochially percieve as "complex organisms".

DO NOT place an unstated assertion on someone else's statement without having investigated what they may have *correctly* meant.

You are one ugly bastard...

@V-2

Actually, the more modern origin-of-life theories put the origin around hydrothermal vents (and there are some compelling chemical and energetic arguments to back this up). If this is true, then we should microbial life emerge very quickly indeed on any body that has a hot rock/liquid water interface.

Moon forming impacts would appear to be fairly common in the formation process of Earth like planets.

This does not mean that Earths are common - but it's not freakishly uncommon. The longest and possibly hardest step on Earth as far as intelligent life is concerned was the changes in geochemistry to allow an oxygen atmosphere - which took several billion years. Once that atmosphere was present, we went from primtive Chordates to humans in just 500 million years - barely 10% of the planet's history.

Which is interesting. The bits that people emphasize - origin of life, and emergence of intelligence from worms - both happened quite quickly, geologically speaking. But inbetween we have ~3 billion years of microbial life. Which means that in all probability, there are a LOT of earth-analogs out there that have plenty of microbes; especially those around smaller stars that may have slower photosynthesis.

(Those around larger stars may get toasted before they get oxygen)

Hi,I think that human being on earth never will be able to travel to other solar systems of our galaxy but manmade robots will be able to make future wave form robots that not only make huge changes in our galaxy but also in whole universe in next 20 milliard years.

Hi,I think that human being never will be able to travel to other solar systems of our galaxy but manmade robots will be able to make future wave form robots that not only make
huge changes in our galaxy but also in whole universe in next 20 milliard years.

AHuman being on earth with highest technology in universe from big bang theory till now.I am almost sure that, human being on planet earth is the only inteligent one that reached to electrical technology in universe even with more than1000000000000000000000000 planets;because of the following reasons:1- we know that life period in our planet is more than 3 milliard years. 2-we know that our technological improvement includes two periods: a- before electrical technology b- After electrical technology.3- we know that our milky way galaxy is more than 13 milliard years old and it's diameter is only 100000 light years.4-suppose that just a few planets in our galaxy or in our nearest galaxies had the same conditions as like as our planet earth just one to five milliard years before our planet earth and reached to electrical technology 1 to 5 milliard years before us;then,didn,t they send their electrical technology robots around most stars of our galaxy ;so,we should receive intelligent made signals from some of those phosil robots(the programmed robots that had used stars' energy to rebuild or reprint the same as they were made ) to rotate around all stars of our galaxy .4- If we accept that we can send missels faster than comets in space in our solar system ,so if we add the time that a comet with life came toward us plus more than 3 milliard years (life period on earth)ago,and the higher possibilities for more comets with life of the same solar system encounter to it,s nearest planets that had almost the same conditions for life as like as our planet earth so we should have recieved their electrical technology signals when we learned how to get signals from space around our planet earth.so,I am also almost sure that the primitive life began on our earth and life didn,t come by comets to earth.

;because of the following reasons

No we don't. those reasons do not support your claims as a form of proof, they are merely assertions without validity.

please how many planets are there in our iniverse.can someone give me the answer???

i think tha there are 10 to 24 planets in the universe

There are actually 50 sextillion, or 5×10(to the power)22, or 50,000,000,000,000,000,000,000 planets in the universe ( not our solar system). This is just theory and approximation, astronomers have never observed all of them.

Shape of universe. I think that accelerating exspansion of universe is constantly equal to pi (3/14*radius)and the shape of universe is constantly spherical and increases(accelerates)in it's spherical form,and the reason is not because of dark energy but because of rules of gravity in matter. We see that in our planet earth the heaviest elements are in core and the lightest elements are in atmospher in gas form and gravity causes the shape of our planet remain almost spherical,hence in universe gravity should cause that the biggest blackhole locate almost in the center of universe as a core and smaller galaxies to incline toward the outer sections of universe in an almost spherical shape as our planet is almost spherical shape.

I think that accelerating exspansion of universe is constantly equal to pi (3/14*radius)

What are the units?

Pi *radius in power 3 (3/14*radius in power 3) and radius is apparentlry between 7 to 14 mllliard light year at least.

wow its so amazing
God is able
do you think about our universe....i have world to define this.
its undercover and unclear for us.
but its matter in God power.
because God create our universe

god is a fiction.

If anyone thought it existed,they wouldn't bother with jails, courts, and so on, they'd just let god sort it out.

But you don't, do you.

Because even you don't think it exists, and you have to do its work here and now.

Just blather on about it on a religious site, retread.

No end, there are more..... and more....... and more.

Thats interesting

Yea God is just so amazing creating all this wonder and beauty! WOW

What god?

*Which* god?

Thank Vishnu? Or is it thank Marduc? Thank Chronos? Thank goodness they're all equally likely to be right, therefore all wrong.

Thank god? Nah, I'll chalk it down to reality rather than the presupposition of a myth.

I think that our universe is spherical and it is rotating and it is moving because of the following reasons: 1- we know that logically we have unlimitedtime and space. 2-we know that we have a universe with gravity and matter now. 3- we know that when something changes to somthing else once ( here our universe) in a limited place and time ,it could be repeated and it will be repeated many many times in unlimited space and time ,so there should be many many universes around our universe. 4-we know that in our universe everything is moving and our universe is moving too. 5- It is moving from one place to another place because of interactions between it, s gravity and the gravities of other universes . It is rotating because it contains different gallaxies with different gravities and densities in different parts of it, so when our universe was moving in space, the gravities of nearest universes interacted with the more density parts of our universe and caused our universe to begin to rotate .THE second thing that causes our universe to rotate is by the bigger gallaxies that flew away from the surfase of most gathered gallaxies witch remained and made the main mass of our universe and these bigger gallaxies turned around main mass gallaxies freely and usually faster than the inner mass gallaxies in an elleptical form.7- It is increasing it,s expansion because of a- eccentric power while rotating b- the gravities of other universes around it.8 - the almost unique accelerating expansion of our universe is for it,s rotation too.

"1- we know that logically we have unlimitedtime and space."

This is absolutely not the case.

Logically, it must be limited. Our best models would support a limit.

Given that your claim is based on the propositions you hold and the VERY FIRST ONE is false, this is sufficient to indicate your conclusion is faulty.

Just as a claim of "all swans are white" is disproved by the existence of a single black swan.

The reason that I think logically time and space should be unlimited : 1-suppose that big bang theory is a fact in forming our universe and it begun at a specific time and suppose that forming our univrse is the same as formig the life on earth 2-both of them need duration of time and need space(place).3-both of them are the result of changing of something to something else that were absent in their new form.4-Can we imagine that before forming the life on earth we had no passing the time,surely not ,and so we had passing the time forever before forming of our universe and so about the place(or space)

None of those suppositions lead to your stated conclusion. And #2 and #3 don't actually pertain to the theory you are supposing to be correct in #1.

And for #4, the formation of life on earth was several billion years after the big bang.

Go check wikipedia for the big bang and read up on the popular explanation of it.

I also note that these are a very different list from what you tried earlier.

Give what you've posted so far, it may be worthwhile to try a different tack to see if there's something constructive to go through here.

Lets go right back. Does it matter if space is infinite and time infinite at all? What would that being correct be able to do or preclude that you wish to find this to be the case (or not)? E.g. "It makes more sense to be if it is infinite" isn't a reason for it to be so: the universe doesn't have to make itself understandable to you to exist. But if there's some feature that you think it would get as a consequence, then maybe looking at that feature would be more fruitful.

It may be that that feature is known to exist by other means. Or known NOT to exist, therefore evidence of a limited space/time for the universe. Or it may be the feature doesn't matter. E.g. "Well, how could the universe form if it had to start?". There are answers to that query.

At the moment, though, you have made claims and post-hoc raised excuses to support that claim, none of which appear to be either valid or supporting your conclusion, so all that's left is to say "It doesn't work that way". Which appears to make you think "I need to find a different explanation of why the universe is infinite", and that merely wastes everyone's time and effort.

Hence my suggestion we find out what it is that you need an infinite universe for.

Help me answer this question. Mention three planet found in the universe?

@Yunusa shekuru #179: You may find the following useful: https://en.wikipedia.org/wiki/Lists_of_extrasolar_planets

Apparently one of the most important puzzles in cosmological phisics is dark energy while our universe before big bang was a strong typical of dark energy for it's sorundings and this can be one more reason for existing multyverse as dark energies for expanding our universe and for causing of begining of our universe's big bang by the sum of their whole gravities.

I love to read all update about https://twitter.com/MBRSpaceCentre

You will find all the answers to your question here. Check this YouTube video out.

https://www.youtube.com/watch?v=nWE19O36a4U

Well, no, you won't. It's just how to google for images of the night sky, and that's it.

Somebody is fluffing up their google ranking (and therefore payment)

this really answered my question! Thanks so much!!!!!

it hunt my head

I loved the article, and the approach to coming up with the estimate. Do you have some sort of academic source (such as a peer reviewed paper) that has an estimate I could quote for research purposes? Thanks!

try doing some research for your research purposes...

Sigh.

it look so creative. with power of wisdom

thank you so much, may you please do an answer to 'how many stars are in the pillars of creation' AKA the hand of god.

again, thank you ever so much

yours sincerely, space girl

The pillars of creation aren't known as the hand of god.

Read

https://en.wikipedia.org/wiki/Pillars_of_Creation

Maradona's use of his hand to score a goal in the world cup was. But there is only one star in that. Maradona himself.

And since the area is only part of a larger nebula and that it is a dark obscured nebula, therefore not possible to look inside, all counts of stars in there would be guesses.

Given the longest part of the region is four light years across and it's therefore not liable to be more than 16 cubic light years (and very likely to be less than half that), comparing with other dense open clusters would indicate something less than a dozen stars in there.

Please refrain from using "AKA" which stands for "Also Known As" when it isn't also known as the asserted name. This is deception. Not a good way to start asking for answers.

C'mon Wow - there's no need to accuse other commenters on trying to deceive people when they've just made a simple mistake.

The 'Hand of God' is a well known name for the pulsar wind nebula B1509. Here's a NASA article on the subject:

https://www.nasa.gov/jpl/nustar/B1509-pia17566

It's an easy enough mistake to make to conflate the two fairly similar images - the later HST image of the 'pillars' do look like a hand as well.

A word of advice -
If you meet someone in public who is fascinated by the subject but happens to mix up two pictures, don't make the mistake of rebuking them for deception. It may be considered incredibly rude and unproductive, as well as, perhaps ironically, deceptive.

"C’mon Wow – there’s no need to accuse other commenters on trying to deceive people when they’ve just made a simple mistake."

True.

But it has to be that it IS just a simple mistake and not deception for this to apply here.

You should not accuse other people of malice when they merely have concluded differently from you.

"It’s an easy enough mistake to make to conflate the two fairly similar images – the later HST image of the ‘pillars’ do look like a hand as well."

It is not known as the hand of god, though. This is plain fact. And that didn't show any reason to believe it was.

MOREOVER, there was absolutely no need for calling it that. So why was it called that? To interject god into a science thread? Why was it said OTHERS in sufficient numbers called it that so it was "AKA"? Argumentum ad populum? And this is about how many planets are in the universe, not how many stars, so why bring up number of stars at all? And given we have thousands of such stellar nurseries in our solar system, and additionally that this one here is not an actual separate nebula, but a very small section of a much wider known one, why was this one specific cherry picked to ask about? To bring up the pillars of creation (which won't have any planets yet, most likely) and thereby also bring up god, in a science discussion again?

A word of advice, there are thousands of godbotherers who cannot let anyone else believe differently. Whether christian, muslim, bhuddist or scientologist, they will kill people for not believing like them. And just because they see god everywhere doesn't mean that their fascination with it should pollute every discussion in the world. Doing so is incredubly rude and unproductive as well as, ironically, deceptive.

Not to mention proffering without any proof or conjectured evidence for being rude, unproductive and deceptive such as you do here is, ironically, all those negative things. Maybe you should wonder if you're building planks in your own eye so that you can be a hero defending the weak for perceived splinters in other people's vision.

I would ALSO note, Marc, that it was entirely ignored that I not only gave the best answer, but also the derivation, so I answered the query.

However, being helpful to someone posting offtopic is unimportant if you're looking for crimes committed by others to persecute.

Going online vigilante is rude, offensive and unproductive.

We're back to that again, aren't we? Maybe there's a problem with starting off with "rude" and building up under the "rule of three" or "rule of repetition" in rhetorical techniques here. Because "rude" is subjective,and therefore not something that can be defended, since it requires the accuser to accuse the other of error without knowing the thoughts of the accuser. Feel free to think "Well, that's rude" then fuck off. Irony.

wooooooooooow

@Phil Shafer, #8 comment

i too have been thinking about how to visualize such a big number so how about this :

10'24 planets....

If you covererd whole the land area of planet earth with a grid of squares 0.01mm x 0.01mm (so that there are 10,000 in each mm2) you would have approximately the same number of squares in the grid as planets in the know universe....

1mm2 = 10,000
1cm2 = 1,000,000
1m2= 10,000,000,000
1km2= 10,000,000,000,000,000 (10'16)
1million km2 = 10,000,000,000,000,000,000,000 (10'22)
148million km2 (earth land area) = 1.48 x 10'24

There are 13 planets in our universe.. Today there are 9 that we are 100% sure of .. The rest will be discovered soon ☝️:)

Apparently 99/85%of our solar system,s mass is our sun and the planets and the rest are just less than0.2% ! Doesn,t the visible tails of spiral galaxies which are apparently more than 10%mass of the whole mass of a spiral galaxy guide us to this result that the primitive cloud that was making our solar system,the percentage of cloud which separated from main mass (sun) and made planets was much more than 0.2% and even more than 10% and went enough away from our sun by eccentric separation speed more than the eccentric separation which our solar system,s remain planets had and went and made wandering giant masses and continued their way to reach to another solar system,s gravity in their way and were accepted as guest planets for those solar systems.

Aren,t the stars of most binary stars the result of joining of two wandering stars which each star was separated from primitive cloude of a super massive solar system,s eccentric separation of poly star which left by the primitive speed which their separated cloude had gotten not to remain in the limitation of their poly star solar system and wandered away till reached each other and made the binary stars.

No, most stars are multiples because the gas cloud that formed the stellar nursery holds thousands of solar masses of gas to collapse, and the collapse necessarily causes the volume stars can form in to be limited.

So it's far far more likely that stars will form randomly close enough to each other to bind gravitationally than so spaced out that they do not interact closely.

Just like it's more likely to get a run of three consecutive numbers in the lottery roll of six numbers of 49 than to get no sequence at all.

If our solar system,s primitive cloud was 100 times larger didn,t we have a big central sun and many shiny(star form )planets orbiting around it.

Apparently most physicist accept that big bang theory has the first acceptable posision among different theories in forming our universe with using of telescopes and other things and accept that these trillions*trillions huge masses practically can collapse as small as a point ,and the passing the time in differrent parts of this expanded universe changes ,in my opinion inside of our universe and outside of our universe mightly have a constant (time passing) and what we consider as a different in passing the time might be only the different in dimension of changing matter and antimatter and what we observe as passing the different time in different parts of our universe be just different form of changing in differrent conditions of matter and antimatter in different parts of our universe.

In our very big universe there must be milliards of systems that their primitive cloud were less than smallest stars and have made the without shining central terestral masses with many orbitals with about our moon or smaller masses which turn around them and mightly smaller sattelites which orbit around their moon size masses in invisible part of our universe .what is the name of these form of systems and their central terestral masses and their orbital masses and masses which orbit around their orbital masses.

I think that in our universe, all sollar systems which have about the same size of our solar system have averagely a host planet or a host satellite In their orbitals.

P.s.and an averagely host planet or host sattelite crashing in their solar systems.

Do you ever listen to anyone else, or is this just generated internally and vomited out for personal gratification?

I subistitute the words,,guest planet and guest sattelite instead of host planet and host sattellite in my two previous comments.

,,Do you ever listen to anyone else,, I would be thankful if you read comment (204) accurately and then give me your new answer.

(To wow) I would be thankful if you read comment (204) accurately and then give me your new answer.

Sorry, please execute your own reading. You asked a query in 205 and it was answered in 206 and never acknowledged nor changed the meaningless burble spewed up by your keyboard.

Indicate there's some vague hominid reasoning going on on that side of the internet.

Sorry, please execute your own reading. You asked a query in 205 and it was answered in 206 and never acknowledged nor changed the meaningless burble spewed up by your keyboard.

Indicate there's some vague hominid reasoning going on on that side of the internet.

Else this is proving that you've nothing to say in 204 and reading it will not advance a damn thing.

I am not a phisicist but I think that there is a direct relationsheep between dark mater and inflation in our universe,so that if the speed of inflation in our universe was more or less than now, then we had more or less dark mater (invisible mater) with respect to visible mater. meanwhile I apologize if my comments are not enough understandable ,it is because english language is not my mother language.

"I am not a phisicist "

Plainly obvious.

"but I think"

No evidence of this.

"there is a direct relationsheep between dark mater and inflation in our universe,"

And definitely none for that.

Tell me, do you just make shit up and then think it's right? If so, what limits do you put on it, if any? If not, what ARE those limits, why do you apply them, and how?

And if your native tongue is not English, then talk in the language of maths which is far more precise and accurate. Or discuss them in a site that does use your native language, not here.

Babbling about half-thought (if that) ideas in a language you don't understand on a subject you also do not understand will only ever result in you looking like a clueless moron.

If you ARE a clueless moron, then this will not phase you in the slightest. If you AREN'T, then this is why you will need to firm up your ideas elsewhere where at least the incomprehension of language doesn't interfere.

this is something beyond our imagination humanity can only understand the secret of this Universe if we can only travel like the speed of the light gazing the skies and using telescopes will not help

I feel lonely in this universe I would like to have some friends in the milky way galaxy

Although humanity has been living on this planet for several million years we had reached great success we put foot on the moon so another million years or so where do you think that human will reach I am sure that they will reach where Kepler is now hunting planets in this nearest constellation but please you must know the difference between cosmos time and human time in cosmos time several million years are only matter of days in human time it is like doomsday

I ultimately believe that human beings will conquer the universe and they will inhabit all those life supporting planets out there , we are at beginning of the journey , our lives will not be confined on this mother planet , it will expand , expand in the whole universe . Humans navigation history taught us that , it never stops in a time. That journey may take a billion year , for cosmos time that is not too far . But my big worry is if humanity will survive on this planet for another billion year . I wish if I had lived after a billion year to witness that great evolution of Mankind.

Do not worry this universe belongs to you and waites you

Our true success depends our knowledge to space

With such a fast universe with so many galaxies and so many solar systems in each one, I don't believe for one minute that the big bang resulted from nothing! that to me would be more bizarre than believing in Father Christmas!

Is true that humanity was created from star dust ?

Is it true that humanity was created from star dust ?

@Ibrahim boodbook #227, 228: Yes. _Everything_ is made of stardust. Only hydrogen and helium were formed in the early universe, and condensed to become the first stars. All other elements were formed either during the lifetimes of stars, or in supernovae at the end of stars' lives.

Ibrahim boodbood:
“Is it true that humanity was created from star dust ?”

Well, Michael Kelsey says, YES!
Basically, the Big Bang banged, stars were formed…..
and the stars became you!
[At least that’s HIS story. And he’s sticking to it.]

Everybody is a star, Ibrahim.
But perhaps more in this way, I’d like to think:
https://www.youtube.com/watch?v=m29F4FtVo-U

Just mind blowing. Caleb Scharf wrote a book called The Copernicus Complex which I massively reccomend if you enjoyed this.

"I don’t believe for one minute that the big bang resulted from nothing! "

Who cares what you "believe", Dan.

Peter Sutcliffe "believed" Jesus Christ spoke to him and told him to kill those women.

ISIS murders "believe" Allah is telling them to behead those heathens.

It's a hell of a lot more believeable that the universe came into existence out of nothing than something that can create universes came out of nothing first.

I know we don't like to hear words like "never" when it comes to Science. But people some are you talking about traveling 186,000 miles per SECOND. for me its hard to see it will get accomplished, its just not the speed alone. There are so many other variables.

Well, we already have science saying "we will never reach the speed of light", even without any other variables.

So, OK, but what is the relevance of these other unnamed and unformed variables? Do they even exist?

To: wow

Forgive me for saying/asking but you strike me as an Atheist. Personally i can't understand that. Not to be a pessimest but mandkind is probably closer to the end rather than begining of existence. My point here is mankind 'in a million years' will never reach the intelligence level to ever come close to understanding the universe let alone life itself. Frankly who are you to suggest god doesn't exist or 'you can't prove it'. By you own relegion 'science' it's incalcuable to explaine the universe in any other way. That to me seems as improbable as saying life is not existent anywhere else in the universe.

Forgive me if i've given any offence it is not my meaning.

To the author: thank you much for the analysis as you've answered some questions i've had.

In every minute of my life I always think and eagerly waite what is the amazing real story that will come out from this universe i have never admired anything else than universe . most people seem never mind this

In every minute of my life I always think and eagerly wait what is the real amazing story that will come out from this vast universe I have never admired anything else than universe I always imagine and accumulate this vast universe in my small mind but most people seem never mind this.

Sometimes I feel powerful that I can exploit the universe and i can control it like a property and sometimes i fell that i am weak and only the product of small particles of dust mixed with water and will immediately go back to dust and become another form of energy that will be beneficial to the life existing above earth .

Every thread (not sure if that's the right word) has the subject changed to basically religion and inconceivable theories which are essentially different versions of "I don't understand the subject so someone must have done it i.e. God".

Who changes the subject to this every time?

The fucking Godbotherers. EVERY TIME. Basically anything on this site that is to do with universe theories that is older than about a day will have a Godbotherer in it. LITERALLY.

If you are a Godbotherer, then leave this site. Nobody here wants to hear your deluded speeches that basically say Goddidit. NOBODY CARES. You can believe what you want but just don't come to this site because it has nothing to do with religion.

space is coolllllllllllllllllllll

i am shocking to listen listen that scientist are searching planets like earth but it is not necessary that life can be possible on earth for its situation it may be that another planet it is not necessary to take oxygen for life and water for life if on earth plant will take carbon-dioxide and release oxygen than at other planet aliens may be take nitrogen for life it will be possible, scientist will search every planet for life not should be like earth only

"Forgive me for saying/asking but you strike me as an Atheist. "

Everyone is to better than 99.99% an atheist.

"Personally i can’t understand that."

Why?

" Not to be a pessimest but mandkind is probably closer to the end rather than begining of existence. "

Well, that's no reason why you shouldn't be able to understand someone being atheist. It doesn't even make sense.

What is puzzling me is up to now that there is no real answer or understanding the mystery of this universe , but I hope that the unthinkable of the present time will be thinkable and easy for the man who will be living on this planet for another million year . Technology was only possible for human beings after staying here for several million years .

hi this is amazing to hear that there are hundreds of planets in the universe

Well, we can always thank science for all these marvelous discoveries.But one thing remains the same,"our little mind is too small to comprehend how big the CREATOR is'.
you may call him,God,Allah,Jah etc.
and this is the God we are messing with...........?
we're fucked up..
When i see all these thing,it motivates me to worship the creator.
I was watching an Islamic video the other day,and it said,He is the creator of Seven Heavens,all what we are seeing is within the first heaven,there are 7 sevens.

No, Joshua, I created the universe. Want proof? Stick your head out the window. See all that stuff there? Think it made itself? No? That's because *I* made it!

But I can tell you, as the creator of the universe and everything else, there aren't seven heavens. It's just a metaphor.

Sorry.

But if you want one, you go ahead and build an everything yourself. See how easy it is, huh? THEN you can start complaining about things going wrong. It's not easy being the creator of all reality, you know.

The best is yet to come the time is fives to twelve, open your mind people and think out of the box.
I look at the Solar System of Planets and I live within that moment of each day seeing something new every day.
Keep searching there no end
James Willams

There's Water on Mercury, and EVERY World Like it!

esiegel — Fri, 30 Nov 2012 18:11:37 +0000

There's Water on Mercury, and EVERY World Like it!

"You don't drown by falling in the water; you drown by staying there." -Edwin Louis Cole

Our Solar System is -- at least from our perspective -- the most well-studied system of planets, moons, asteroids and comets in the entire Universe.

Image credit: Olaf Frohn, from earlier in 2012.

And in this system, the closest planet to our Sun, Mercury, was also one of the most poorly understood planets until very recently. Because Mercury is so close to the Sun, it's very difficult to view it under good conditions with a telescope; the risk of ruining your optics by exposing them to direct sunlight is tremendous! (Hubble has never imaged Mercury for exactly this reason.) You have to wait until after sunset, and even then, Mercury is so small and distant that ground-based telescopes can barely resolve features on it.

Image credit: Boston University / Baumgardner et al., 2000 (Astronomical Journal).

It was only in the early 1970s that we got our first good picture of the planet Mercury, thanks to the Mariner 10 spacecraft, which was the first NASA mission to visit the innermost world in our Solar System.

Image credit: NASA / JPL / Ted Stryk, 1974.

As we anticipated, Mercury bears a strong resemblance to our Moon: it's a rocky, heavily cratered, atmosphere-less object in the inner Solar System. But one thing you may not realize about Mercury is that it also has another feature in common with the Earth's Moon: unlike the Earth, it's hardly tilted at all with respect to the Sun!

Image credit: Calvin J. Hamilton.

In fact, of all the planets in the Solar System, Mercury has the smallest axial tilt of every one! On Earth, our orbit is a nearly perfect circle around the Sun. Yes, it's technically an ellipse, but when the Earth is farthest from the Sun, it's really only 3.5% farther away than when it's closest to the Sun. This is why our seasons are determined by our axial tilt -- a significant 23° -- rather than the eccentricity of our orbit. (In fact, Earth's winter in the Northern Hemisphere corresponds to our closest approach to the Sun; the effect of axial tilt dominates by far!)

Image credit: Physical Geography; http://www.physicalgeography.net/fundamentals/6h.html.

But the opposite is true on Mercury; it's actually the most eccentric planet in the Solar System, a full 52% farther away at aphelion than at perihelion! Because its axial tilt is virtually negligible -- at 0.1° -- it's the ellipticity of Mercury's orbit that determines the seasons on that world. So unlike the Earth, which has each of its poles see six months of daylight followed by six months of night, Mercury's poles always have the Sun appear just at the horizon, on the border between night and day.

Image credit: AP Photo / NASA / JHU Applied Physics Lab./Carnegie Inst. of Washington.

You might be wondering about those shadows on the pole itself; this is actually a very similar story to the Moon. The Earth's Moon is tilted at just 1.4° with respect to the Sun, meaning that the Sun's rays are always grazing the poles of the Moon.

Because the Moon is heavily cratered, including at the poles, that means that the polar regions that have deep enough craters close enough to the pole itself will never be exposed to direct sunlight!

Image credit: NASA / GSFC / Arizona State University.

These regions of the Moon that live permanently in shadow are worse than the Thunderdome: two men enter, no man leaves. The reason the Moon has no atmosphere is because direct sunlight on the surface of the Moon is energetic enough to impart any atom or molecule it strikes with enough velocity to escape the Moon's gravity. So the entire surface of the Moon is devoid of water molecules, hydrogen gas, oxygen, methane, ammonia, or nitrogen. It's only the heavy rocky particles of the Moon's outer surface that remain behind.

But inside a permanently shadowed crater, the temperature is somewhere around a cool 50 Kelvin, and once you fall in, you're never coming out.

Image credit: NASA, ESA, D. Jewitt (UCLA).

That includes materials from comets, asteroids, and anything else that lands on the surface of that world. And of course, comets and asteroids are loaded up with our favorite compounds: water, methane, and ammonia among them!

So it's no surprise that we've found both water and organics (any molecule with a carbon bond in them) inside these permanently shadowed craters on the Moon. And it should come as no surprise that -- with the advent of dual imaging from Messenger and the Arecibo Radio Observatory on Earth -- both water and organics are found in the pits of these permanently shadowed craters on Mercury, too!

Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Carnegie Institution of Washington / National Astronomy and Ionosphere Center, Arecibo Observatory.

Don't get me wrong; it's a great discovery! But it's also a completely expected discovery; bigger news would have been if they hadn't discovered water and organics in these permanently shadowed regions. As scientist Sean Solomon stated:

"For more than 20 years the jury has been deliberating on whether the planet closest to the Sun hosts abundant water ice in its permanently shadowed polar regions. MESSENGER has now supplied a unanimous affirmative verdict."

This wouldn't work on Venus or Jupiter, whose atmospheres would prevent permanently shadowed craters from harboring material indefinitely, but it does confirm what we thought, and allow us to make a convincing leap to other Solar Systems with some certainty!

Image credit: European Southern Observatory.

Around any star, any rocky planet with no atmosphere and a sufficiently small axial tilt should have permanently shadowed craters at its poles, which will contain ices and other frozen materials common to that Solar System. Finding this water and these organics in the permanently shadowed craters of Mercury isn't a surprise; it's exactly what this picture predicts. Unless you're super-close to your parent star (and remember, folks, that Mercury is still over 50 million km from the Sun on average), that sunlight won't be able to get in there and kick those particles out!

And that's why there's not only water on Mercury, there's probably water on every Mercury- and Moon-like world out there!

esiegel Fri, 11/30/2012 - 13:11

Tags

This discovery is near and dear to my heart because I have developed an electrostatic separator that can separate ice from regolith via contact charging.

http://www.isruinfo.com/docs/srr12_ptmss/36-Concentration%20of%20Lunar%…

It works by contact charging. When two materials contact, at the point of contact the electrons must have the same energy. To accomplish this, a potential is generated (the contact potential). In the field-free state, it takes a certain energy to remove electrons from the surface to infinity. This energy is called the Work Function. It is a characteristic property of materials. When two materials contact, in order to equalize the energy of the elections at the point of contact, the two materials exchange charge until the contact potential difference equals the difference in work function. When the materials move apart, the contact is broken, the charge cannot leak back and particles develop a charge characteristic of their composition. This is the charge that I use in my separator.

I have demonstrated separating crystalline ice from ground basalt simulating lunar regolith (see above presentation for data). This was a trivial separation. That work was done more than 20 years ago, and the separator has since been commercialized on separating unburned carbon from flyash.

We can process material at ~ 1 kwhr per ton processed. This is a few orders of magnitude (at least 2, more likely 3 or even 4, orders of magnitude) less energy than what would be required to heat the regolith plus ice hot enough to drive off all the water via evaporation. I estimate that a 50 kg machine would be able to process 5 tons per hours using 5 kw.

This savings in energy is so much as to be enabling.

If ice is to be recovered in these cold places, my separator will be used to do it.

Ethan
Very nice explanation.

But you haven't explained why, "comets and asteroids are loaded up with our favorite compounds: water, methane, and ammonia among them!" Why?

"we have proposed that asteroids incorporated during their formation icy particles formed in the outer Solar Nebula... In spite of the growing pool of evidence pointing towards the existence of water ice in the Main (asteoid) Belt, its detection on asteroids is a challenging observational problem." arXiv:0710.5179

So we don't really know, we just have proposals of how the ice formed and then got incorporated into asteroids and comets and...

My speculation is simply that you take hydrogen gas and oxygen gas (formed in some supernova) and a little spark (or maybe the right EM radiation in space) and voila you get a water molecule in space that then coallecses into a comet or asteroid and planets.... but...

"The primordial Earth was a seething ball of magma, so the water that it began with would have evaporated into space. As a result, planetary scientists have long debated which of two types of objects, comets or asteroids, were more responsible for delivering Earth’s water. A new study, published today (12 Jul 2012) in Science, says that asteroids were the source." http://blogs.nature.com/news/2012/07/study-says-asteroids-delivered-wat…

Any better explanation/ clarification of how does water gets into asteroids would be appreciated.

OKThen, great questions. But a little peek in Wikipedia would have answered them quickly, I'm sure. Anyway, here goes:

The basic theory on water is based on observations of how volatiles are plenty, and besides giants or freshly supplied moons (Titan), are frozen in the outer system. Especially for water the radiation from the young Sun would have set up an "ice line" (aka "snow line") in the protoplanetary disk.

This would predict the mass content of water in asteroids, where the majority has ~ 10 % water by mass, and comets much more. It would also predict the dryness of terrestrials, who have ~ 0.05 % water by mass. (But see the tension with later models as described below, where the problem is to get rid of the water in the first place!)

Luckily, or we would have no continents.

Recently it has been suggested that the same would happen with carbon, a "soot line". Carbonaceous chondrites have a lot of carbon, and it is predicted that superEarths accreting outside the soot line could have ~ 30 % carbon crust by mass.

Luckily we don't have that as it would set up an outer diamond crust and bar cells from necessary metals to make vital ribozymes or enzymes. Instead we have siliceous minerals.

But, to finish this story, it is unlikely that asteroids and comets have supplied inner terrestrials with a dominant part of water. The hydrogen isotope D/H ratio of asteroids is ~ 2 times larger than Earth since they formed in a colder part of the disk. And comets are worse by many orders of magnitude.

Instead the roughly same water content found in Earth, Moon and Mars initial mantle by various samples (zircons, Apollo samples, martian meteorites) can be predicted by a disk mechanism, as opposed to the differential rates suggested by impactor delivery. Recently such an innate mechanism was found. [ http://astrobites.com/2012/07/25/snow-lines-and-protoplanetary-disks-or… ]

"Consistent with previous work, the turbulent model has the ice line crossing an AU just about a million years after disk formation – barely any time to form planets! By contrast, the model that includes a turbulence-free dead zone has an inner icy region and a central ice-free region. The latter is attributed to a small amount of turbulence due to self-gravity that heats the outer region of the dead zone.

This is very exciting – after t~1 million years, there is a growing ice-free region right around the Earth’s orbit! This resolves the discrepancy of previous models, and provides ample time for an ice-free Earth to evolve. Further work will be necessary to validate this model. If it proves consistent, then we may have reconciled planet formation theory with the water-poor Earth: Regions of low turbulence in the protoplanetary disk allow formation of water-poor terrestrial planets."

On the other hand it is known _some_ late bombardment by asteroids was present, or we would have little to no rare earth metals in the crust.

Note by the way from the figure in the link that Mercury, now at 0.3 - 0.4 au, could have been within the dynamic inner icy region most of its formation time. Water as from such a source in terrestrials comes from hydrogen and oxygen trapped in the mantle material, which are later released by volcanism and reconstituted as water sooner or later. Mercury should have a higher innate water content (by mass) than Earth has, and it may well be that some of the ice we now see has its source within rather than without.

Not all asteroids contain water. But there are "water-bearing" asteroids that contain large quantities of water ice and other frozen volatiles. Some get deflected into the inner regions of the Solar System. They are very black and due to this low albedo (~0.02 --- similar to carbonaceous chondrites) they get very hot from solar heating when they come closer to the sun than Mars. The explosions of steam and other volatile gasses would propel particles of dust, water and ice out from the core and the solar wind would push it into a long tail in the anti-solar direction. If observed by humans they would say "look at the long tail on that beautiful COMET" not "look at the long tail on that comet-like asteroid." Liquid water in these bodies would cause aqueous alteration of minerals such as we see on CI1 meteorites (Orgueil, Ivuna, etc. ) and the cubanite grains returned by Stardust from comet Wild 2. The periodic presence of sunlight and hot liquid water and cold liquid brines provide suitable conditions for the growth of filamentous Cyanobacteria within pools within the rocky and icy crusts of comets or water-bearing asteroids. This could explain the presence of the fossilized remains of recognizable cyanobacterial filaments that have been found embedded in the rock matrix of these meteorites. The low nitrogen levels in these filaments prove that they are not modern blue-green algae that invaded the stones after they landed on Earth. The presence of mmicrofossils in CI1 and CM2 meteorites combined with the valid detection of organics and water ice at the poles of Mercury, Mars, and the Moon as well as on comets and "water-bearing" asteroids implies that life is probably very widely distributed throughout the Cosmos.

Here I think I'm asking a sensible question that is not a in controversial area of astrophysics.

So AT FIRST, I accept Torbjörn's and Richard's answers as reasonable. But I check and both answer's turn out to be COMPLETE NONSENSE.

Torbjörn's link says, "However, in comparison to the gas giants, Earth is actually very water poor! The Earth is only 0.023% water by mass, while the outer solar system giants are as much as 40% water." COMPLETE NONSENSE, the gas giants aren't 40% water.

"Jupiter's upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume or fraction of gas molecules. " wikipedia No water on the Jupiter gas giant.

Torbjörn Larsson, NO THANKS!! But THANKS FOR THIS HEADS UP that you are selling COMPLETE NONSENSE.

Then a check on Richard's CI1 fossils turns out to be nonsense also.
"CI1 fossils refer to alleged morphological evidence of microfossils found in five CI1 carbonaceous chondrite meteorite fall: Alais, Orgueil, Ivuna, Tonk and Revelstoke. The research was published in March 2011 in the Journal of Cosmology by Richard B. Hoover, an engineer. However, NASA distanced itself from Hoover's claim and his lack of expert peer-reviews." wikipedia

Richard B. Hoover, NO THANKS!! But THANKS FOR THIS HEADS UP that you are selling COMPLETE NONSENSE.

Well, there we have it.
NONSENSE.

WOW, must be on vacation because he would not let this stand for so long.

WOW, we need your help. If I am almost suckered in by this psuedoscience; then others are falling for it too.

"The origin of water on Earth, or the reason that there is clearly more water on the Earth than on the other planets of the Solar System, has not been clarified. There are several acknowledged theories as to how the world's oceans were formed over the past 4.6 billion years." wikipedia

So my question stands.
And on second thought, Ethan's explanation is excellent even though it leaves some unanswered questions. I can wait a long time for a credible answer.

" The interior (of Jupiter) contains denser materials such that the distribution is roughly 71% hydrogen, 24% helium and 5% other elements by mass." wikipedia

OKThen I suggest you should be careful about believing everything you read in Wikipedia.

First, I am not an "Engineer".
I was once called an Engineer by Josef Boehm, of the Peenemunde Rocket Team and I accepted it as the very high compliment that he meant it to be. Others use the term as an insult, but they do not appreciate the knowledge and skill needed to be a fine Engineer. While I have designed and built advanced X-ray telescopes and microscopes, I have also used these instruments for studies of the Sun and Supernova remnants. My job descriptions at NASA were as an Astrophysicist and Astrobiologist --- never as an Engineer.

Second, you obviously never read any of my papers or you would know that I have studied many carbonaceous meteorites --- but never examined Tonk or Revelstoke. Only one gram of Revelstoke was recovered, and I have never had the chance to examine this stone.

Third, the paper in the Journal of Cosmology was Peer Reviewed by experts prior to acceptance for publication. It was also made available to a large number of other Scientists for Commentary, and their comments were published along with the paper. The statement that the paper was not peer-reviewed was simply incorrect. The reasons why some individuals at NASA chose to make such a false statement are still not clear.

Fourth, the morphological evidence is not alleged. It is published in this paper and in many others for the entire world to examine. Your comment that this is "NONSENSE" tells me that you know nothing about Cyanobacteria. I first observed diatoms and Cyanobacteria under he microscope in 1952. I have conducted an intense study of micro algae with both optical and scanning electron microscopes since 1968. In collaboration with Dr. Elena Pikuta, I have discovered, described and validly published two new genera and twelve new species of bacteria from extreme environments. This is hardly the kind of science conducted by "an Engineer".. I can assure you that both diatoms and filamentous Cyanobacteria can be recognized and classified on the basis of their morphology alone. The filaments that are shown in the JOC paper were examined not only by myself, but also by several of the world's leading authorities on Cyanobacteria and trichomic sulfur bacteria.

OKThen, I suggest you read my paper, rather than read what others have falsely claimed that it says. After you have read it, then I welcome any critical comments you may wish to make --- but they should be based on solid science and not just name calling and other such nonsense. Also it would be nice if you would use your real name and state your own credentials in the fields of Astrobiology, meteoritics, micropaleontology and microbiology. Science should always be a search for the truth. I have published the data (both in high resolution FESEM images and Energy Dispersive X-ray Spectroscopy Elemental data) that I have found on micro structures that are truly in these stones. I have presented my evidence in scientific meetings and colloquia on seven continents. Similar filaments have been found by scientists in Russia, Canada, and the United Kingdom conducting independent electron microscope studies of CI1 and CM2 carbonaceous meteorites. Other scientists have also shown that these meteorites contain chiral amino acids, fatty acids, nuucleobases, pristane, phytane, vanadyl porphyrins and other life-critical biomolecules that are both indigenous and extraterrestrial in origin. These are solid indicators of life that provide independent evidence supporting the conclusion that these filaments are both biological in nature and indigenous to the meteorites ---hence evidence of the existence of extraterrestrial life.

Richard B. Hoover
December 2, 2012

Richard B. Hoover

You are correct. I know little about cyanobacteria. And based on the wikipedia entry about you; you do know something. And I am unqualified to evaluate your work. BUT...

I am qualified to have an OPINION based on others who are qualified to judge the merit of your work.

So yes, I do consider the opinion NASA's Chief Scientists, magazines Nature, Science, Discover and others; in forming my opinion.

Your hypothesis is NOT supported in the judgement of your peers at NASA, Nature, Science and as well your "claims were initially submitted to the International Journal of Astrobiology, which rejected the paper." wikipedia.

Trying to win your case amongst amateurs, here on this blog, is not good science.

Furthermore, it is dishonest science to present your ideas to amateurs without acknowledging that you are the author; and that your theory is a highly disputed speculative scientific theory.

Such a disclaimer is (in my opinion) a scientific necessity; even as an amateur I use appropriate disclaimers. (see my above). "My speculation is simply... Any better explanation/ clarification... would be appreciated."

I issue a disclaimer because I don't want to mislead, nor do I want to win by popular argument; I want to learn and understand the science; therefore I am ready to be proven wrong.
ARE YOU READY TO LEARN BY BEING PROVEN WRONG??

So, if Richard B. Hoover,(your) interpretation about cyanobacteria in asteriods is correct; then your argument must be convince credible peers, not amateurs and not the tabloid press. And regardless of your credentials and personal belief in your ideas, THIS BLOG IS NOT THE PLACE TO ARGUE YOUR HIGHLY DISPUTED SPECULATIVE IDEA.

Richard, you say, "I welcome any critical comments... they should be based on solid science and not just name calling."
If you believe this; then you should dissociate yourself from your publisher the Journal of Cosmology.

You lose a great deal of scientific credibility by being associated with your publisher (the Journal of Cosmology). who on your behalf accussed , "NASA, and Science and Nature magazine.. (of having) dressed religion in the language of science... (of making) editorial and scientific decisions based on the Bible and the "Laws of Moses".. (of being) lunatics (who)... throw filth upon the reputations of legitimate scientists."
http://daviddobbs.posterous.com/cosmology-journal-declares-war-won-enem…

So yes, in MY AMATEUR OPINION, your research conclusions are unsupported.
Your "Pigasus Awards... from the James Randi Educational Foundation for the dubious honor of being among the 5 worst promoters of nonsense .. (for your) paper in the eccentric Journal of Cosmology" is well earned. Los Angelos Times, Apr 1, 2011

"The Journal of Cosmology... (charges) $35.00 Article Processing Fee... (and) a $150.00 Publication Charge... Accepted articles will not be published until the publication fee is received."

"Not all asteroids contain water. But there are “water-bearing” asteroids that contain large quantities of water ice and other frozen volatiles."

So where did this water come from?

If it was just there in the outer system to form on these asteroids et al, then how did they know that they were accreting on an object that was still undergoing accretion to form a bigger asteroid?

" They are very black and due to this low albedo"

Some will. Most I would suggest do not.

But if they were, then this would indicate constituents from organic (or at least carbon-rich) sources.

I think you're a little confused.

OKTHen, maybe you failed to notice that I signed my real name to all of my comments. Since you are hiding behind OKThen, how could I know that you are "an amateur". You make several statements based on Wikipedia that are also incorrect.

First, I was invited to write this article and I paid nothing ($0.00) to the Journal for it to be published. I have never paid to have any article published in any publication.

Second, this Journal of Cosmology article was never rejected by the Journal of Astrobiology. It was written for the JOC at the invitation of a Senior Editor and never previously submitted to any other Journal for consideration. I take responsibility for my own writings and actions, but have never apologized for the words or opinions of others. Perhaps you should also take a look at the scientific credentials of James Randi.

I presented images and spectral data in the article and provided a scientific interpretation of these observations based upon my own knowledge and discussions with many of the world'sleading experts on Cyanobacteria. They are named in the acknowledgements of the paper. Aqain I suggest you read the paper yourself if you wish to know what the evidence really is. The paper is freely available online.

Second, I said nothing about Cyanobacteria in asteroids. I have not examined asteroids. I have studied a large number of carbonaceous meteorites since 1997. Many of them contain embedded filaments, some of which exhibit both the size, size ranges and complex morphologies that are known in certain genera and species of Cyanobacteria that are well-known on Earth. That is an observation that is backed up by the high resolution images in a host of papers published in the peer reviewed articles and conference proceeding by me and several others well-known scientists. These findings are not disputed by my peers (scientists who actually have studied Cyanobacteria and who can classify them to genus and species). In this arena, the opinion of a particle physicist is just as irrelevant as would be that of a general microbiologist on a question of string theory or quantum chromodynamics unless they have also actually studied those fields.

OKThen, Why don't you read the article before you respond? You may change your opinion.

To Wow, please note that water is the most common molecule in the Universe composed of two or more elements. Also, it is a scientific fact that the albedo of all of the carbonaceous chondrites known is very low. These are jet-black stones. It has also been discovered that the nuclei of all comets studied have an albedo that is very similar to that of the carbonaceous meteorites. This was a prediction of the late Sir Fred Hoyle, that has been confirmed by a large number of Space observations.

Richard Feyman advised, "There is one feature I notice that is generally missing in "cargo cult science." It's a kind of scientific integrity, a principle of scientific thought that corresponds to a kind of utter honesty — a kind of leaning over backwards. For example, if you're doing an experiment, you should report everything that you think might make it invalid — not only what you think is right about it; other causes that could possibly explain your results; and things you thought of that you've eliminated by some other experiment, and how they worked — to make sure the other fellow can tell they have been eliminated.
Details that could throw doubt on your interpretation must be given, if you know them. You must do the best you can — if you know anything at all wrong, or possibly wrong — to explain it. If you make a theory, for example, and advertise it, or put it out, then you must also put down all the facts that disagree with it, as well as those that agree with it. There is also a more subtle problem. When you have put a lot of ideas together to make an elaborate theory, you want to make sure, when explaining what it fits, that those things it fits are not just the things that gave you the idea for the theory; but that the finished theory makes something else come out right, in addition.
In summary, the idea is to try to give all of the information to help others to judge the value of your contribution; not just the information that leads to judgment in one particular direction or another."

http://scienceblogs.com/pharyngula/2011/03/06/did-scientists-discover-b… provides in my opinion a credibly reviews and provides links to other reviews of Richard B. Hoover's (in my opinion) psuedoscience nonsense.

I rather trust David Morrison, senior scientist at the NASA Astrobiology Institute at Ames Research Center who said, "Many scientists have examined thousands of meteorites in detail over the past 50 years without finding any evidence of fossil life. Further, we know a great deal about the conditions on the parent objects of the meteorites, which (not counting the few meteorites from the moon and Mars) were rather small, not at all like planets. I would therefore invoke Carl Sagan's famous advice that extraordinary claims require extraordinary evidence. At a bare minimum this would require publication in a prestigious peer-refereed scientific journal — which this is not. Cyanobacteria on a small airless world sounds like a joke. Perhaps the publication came out too soon; more appropriate would have been on April 1."

David is correct in that we do know a great deal about the parent bodies of the CI1 and CM2 carbonaceous meteorites. The mineralogy reveals extensive aqueous alteration at very low temperatures --- from 50 C to as low as -30 C. This proves the presence of liquid water and brines on these bodies, which were very probably cometary nuclei. Cyanobacteria live in liquid water and are present in thin films of water and ice in glaciers and rocks of the Earth's polar regions. I have studied them in Alaska, Iceland, Patagonia, and the Patriot Hills, Thiel Mountains and Lake Untersee in Antarctica. And it is also not a joke that they do not require an atmosphere in order to live. We have also learned much about microorganisms that inhabit the extreme environments of Earth, Microbes live and grow and survive for millions of years in the ice and permafrost of the polar regions, so they as well as many other microbial extremophiles should also be able to survive in comets. David is also wrong in that there have been many publications providing evidence for the remains of Cyanobacteria and other microfossils in "prestigious peer-reviewed" publications such as Science and Nature over the past half century. Ignoring them or being ignorant of them does not make them go away. They are referenced in many of my papers and you would know this if you had ever bothered to read any of them. But iyou have already admitted you know nothing about cyanobacteria and it is obvious that you have no interest in learning about microbiology, micropaleontology or meteorites and the evidence for complex biomolecules and microfossils that has been found by me and many other scientists in some of these wonderful messengers from space. However, there may be others who read these words who may chose to examine the data with an open mind. The images and EDS data are in the papers published on many thousand of others as yet unpublished are on computer hard drives and the samples and several thousand microfossils are still embedded in the meteorites and remain in the labs at NASA and the Russian Academy of Science in Moscow where they can be examined by me and others in the future.

Richard
It is obvious that you understand this subject very well.
And you sound very reasonable.
But as a science minded layman; your work does not pass my standard for credible science. And the standards of a professional scientist are higher.

As a layman, here are a few of my concerns:
1) Cyanobacteria, i.e. blue green algae are found everywhere on earth and have lived on earth for billions of years. So my first problem with your hypothesis of blue green algae living in space is a problem of contamination after the meteor lands on earth.
2) In my opinion, the Journal of Cosmology is not a credible publication. They published your research paper; but it cannot be found on their web site. What can be found is an advertisement and link to buy your book for $49.95 from Amazon.
3) In my opinion you do not heed Feynman's advice to "lean.. over backwards.. (to) report everything that you think might make (your research) invalid". You only tell what you think is correct about your research; you do not address the recognized problems with your hypothesis.
4) You say, "it is obvious that (I) have no interest in learning about microbiology, micropaleontology or meteorites and the evidence ." You misunderstand my role as a layman and your role as a scientist. The curious layman's role is to learn and to ask tough skeptical questions. But it is the scientists role to ask even tougher questions, to discover and to convince other scientists.
5) If you are serious about the merit of your hypothesis; then you need more research, more careful findings, and answers to your scientist critics. None of this name calling that the Journal of Cosmology did about NASA, Nature and Science magazine.
6) You need to republish online in arXiv which has a high enough peer review reputation and yet does publish some controversial papers.
7)You need to engage scientist in your field. Perhaps these scientists.
- Rethinking the Paleoproterozoic Great Oxidation Event: A Biological Perspective by John W. Grula 2012, arXiv:1203.6701
- Hydrogen Greenhouse Planets Beyond the Habitable Zone by
Raymond Pierrehumbert, Eric Gaidos 2012, arXiv:1105.0021
- Transfer of Life-Bearing Meteorites from Earth to Other Planets by Tetsuya Hara, Kazuma Takagi, Daigo Kajiura, 2012, arXiv:1204.1719
- Bacterial morphologies in carbonaceous meteorites and comet dust, by N. Chandra Wickramasinghe et al 2010, arXiv:1008.3860

These papers are not necessarily correct; but they reflect a certain level of peer review and scientific integrity by being published in arXiv. As I am sure that you are aware, that the last paper by N. Chandra Wickramasinghe et al references your work.

Convincing laymen is easy. Laymen believe in ghosts and alien abduction; cyanobacteria in comets or meteroites is easy for a layman to believe. The talk shows and the science blogs are not the place to convince the community of scientists.

Right now scientists think the idea of "Cyanobacteria on a small airless world sounds like a joke." How do you turn that scientific view around? NOT ON THIS BLOG.

You need to engage scientists. If they won't talk with you; then write research papers of the highest caliber. Be proud of your best ideas; but be honest about their merit or NOT.

Be well, have a sense of humor and important people in your life. I've learned from this conversation, Thank you.

And remember, they also laughed at Bozo the Clown.

Skepticism means you're skeptical OF YOUR OWN PROPOSITION.

It's piss easy to be skeptical of someone else's work, but if they're being skeptical of their own work you're rather redundant in the picture.

OKThen,

I am sorry but I do not think you have learned from the conversation. It is obvious that you have never read any of my papers concerning microfossils in meteorites, the first of which was co-authored with the late Sir Fred Hoyle and published in the Journal Earth, Moon, and Planets in 1986. If you had read the Journal of Cosmology paper, then you would know that the EDS spectral data published reveals very low levels of nitrogen in these filaments proving that they could not have invaded the meteorites after they landed on Earth. If you want to read the paper, I can provide a link where anyone can download it at no cost. I have no control over the Journal and am aware that their server crashed many times from people trying to download the paper. I receive no money from the sale of the book, so am not in any way trying to advance its sales. I am writing more papers about other filaments in other CI, CN and CO carbonaceous meteorites

OKThen, I am afraid that as a layman, you simply do not understand the role of a scientist. I have been a professional scientist since I joined NASS in 1966 and have published over 250 scientific papers. The role of a scientist is to make careful observations the natural world and honestly present the evidence and provide his interpretation of what the data means. That is precisely what I have always done. Paradigm shifts are difficult and can take decades or even centuries to occur. Continental drift is just one example.

You say "scientists think the idea of Cyanobacteria on a small airless world sounds like a joke." That is not a "scientific view" it is an opinion. And I do not know any scientists who would state such an opinion, but if they did it would be based on ignorance. Cyanobacteriaia live in water, in glacial ice and in thin films of water between sand grains in rocks in the polar regions (cryptoendoliths). These microbes would have no problem living on a comet, icy moon such as Europa, Enceladus or some other type of a "small airless world." However, if you had read my papers you would know that I do not advance a hypothesis of "blue green algae living in space." I do not know what the parent bodies of these meteorites were, although I think comets make a very logical possibility for a number of reasons. These organisms were living on or in the parent body of these meteorites, which we know contained liquid water, minerals and a host of organic nutrients. An the evidence indicates they died and were fossilized long before the stoned arrived on Earth. You say I should engage scientists. Well, I have Chaired 35 International Scientific Conferences in the United States, Crete, and Russia. These meetings have been attended by scientists (including Nobel Laureates and Academicians) from all over the world. I do not know of any scientist who will not talk with me, and I have discussed these findings with several of the world's greatest authorities on Cyanobacteria, micropaleontology, microbial extremophiles, comets and meteorites. If you read my JOC paper, you can find their names listed in the acknowledgements. I suggest you consider how naive it is to think that the Earth is the only place in the Universe capable of supporting life. There is nothing really unique about our beautiful pale blue dot. As the evidence from Mercury shows, water can be found almost everywhere. And the guiding principle of Astrobiology has always been "Follow The Water."

Richard B. Hoover

I'll admit right up-front that I never expected water ice on Mercury, so this discovery comes as a very interesting and pleasant surprise.

---

Torbjörn & OKThen: It's more fun to speculate first and then look in Wikipedia or wherever. This way you get to find out if you're drawing appropriate conclusions from your existing background knowledge, and if not, the corrective feedback is useful.

---

I wrote the following paragraph after RH's first comment, before reading the rest of the arguement between Richard & OKThen:

Richard Hoover: Is your hypothesis widely shared among exobiologists? Could it be tested by a robotic mission to one of those objects, to attempt to find living cyanobacteria or fossils of same? How would bacteria have transferred to or evolved and survived on objects with conditions that vary so widely as they pass through space?

---

After reading the arguement: It appears the whole thing about cyanobacteria is highly contentious, so I'll probably remember this the next time I see anything on the subject, and be sure to do some skeptical digging around rather than taking any news reports on it at face value.

My Dear Richard
Of course there is life on planets throughout the universe.
And though blue green algae is robust; it does NOT live on meteors in space.
If you don't believe an angel; ask a scientist.

I have never suggested that Cyanobacteria "live on meteors in space." I have reported the detection of the filaments in several carbonaceous chondrites. Many of these filaments exhibit features similar to those known in filamentous trichomic prokaryotes that live in aquatic environments, ice and permafrost on Earth. This is not a claim. It is not a hypothesis, It is not a theory. It is a statement of observational facts. The evidence is provided in the form of ESEM and FESEM and optical microscopy images an EDS spot data and 2D elemental spectral maps. Based on ED'S studies of the nitrogen content of a host of living and long dead biological remains as well as ancient fossils of terrestrial life forms, I have concluded that these filaments can not be modern (I.e. post-arrival biological contaminants.) This leaves the alternate explanation that they lived and died long ago in an aqueous environment on the parent body of the meteorite. Other scientists have proven that the parent bodies of these meteorites had large amounts of liquid water for long periods of time. There are a number of independent studies that have established that these meteorites contain life-critical biomolecules that are not known to be made by abiotic mechanisms. I do not need to believe an angel or ask a scientist. I am a scientist. II have also discussed these observations with hundreds of scientists over the past fifteen years. Have you even bothered to read the paper for yourself? If you do, you may revise your opinion. If not, perhaps you could then state your specific objections to the published data.

You have asked some good and thoughtful questions.
Again, this is not a hypothesis, but observations that are known to a large number of exobiologists and astrobiologists. Many, such as David McKay, Academician Alexei Rozanov, Academician Eric Galimov, Professor Roland Paepe, Dr. Roesmarie Rippka, Dr. Anne St. Amand, and many others have provided helpful discussions and are generally supportive of these findings and interpretations. There are others who are strongly critical. They have not directly addressed the observations and set forth alternative explanations for the observed data.

Robotic missions could be flown, but these would be difficult, and costly and are not likely to be undertaken by NASA. Since Viking, NASA has consistently refused to consider any mission with life detection capability. Note that neither Spirit, Opportunity, nor Curiosity had any instruments or experiments on board designed to search for life.

Cyanobacteria and many other extremophiles have adapted to be able to survive in hot water, cold water and exposure to hard vacuum and high levels of radiation. This combination of conditions could easily be found on a comet, but is not to be found anywhere on Earth. Why did these organisms adapt to be able to survive in conditions that are never encountered together in natural environments on this planet? The parent bodies of these meteorites could have been contaminated long ago by microbes ejected from Earth, Mars, Europa, Enceladus comets, or other bodies of our Solar System. If these microbes found water, nutrients and other suitable conditions they may have begun to fluorish and then die and be cryopreserved for millenia. Fascinating thought is it not. I hope these comments are helpful.

Thanks for the interesting article.

Unfortunately, I then read the comments, and now, instead of wondering about our amazing universe, I'm wondering about how common it is to find rude and argumentative people on sites like this.

On the positive side, I'm amazed that Richard stayed focussed and on task thru all that. Pretty impressive. But, a pity that Torbjörn Larsson sensibly just ignored it all and left, don't you think?

Most people would have realised that 40% figure was just an error (probably referred to sattelites) but not OKThen. Sufficient reason to accuse Torbjörn of all sorts of mischeif, and move the conversation from science to OKThen's ego.

However, loved the 'laughed at Bozo' joke.

How did you get a photo picture to the nine planets?

The Canals of Mars

cevans — Fri, 28 Sep 2012 21:31:40 +0000

The Canals of Mars

The space-heads among you have undoubtedly heard about the Curiosity rover's first significant discovery: the remnants of an ancient streambed on Mars, which would seem to indicate the presence of water in the planet's history. This jagged pile of alluvial rock and dust may not look like much, but it brings to mind one of my favorite pieces of Martian historical arcana.

For a time in the late 19th century, it was believed that there were canals on Mars.

The Italian astronomer Giovanni Schiaparelli, who observed Mars in 1877, was the first to describe, name, and lovingly illustrate mysterious straight lines along its equatorial regions, which he called canali. Viewed with the telescopes of the day, in brief instances of still air amidst the optical strangeness of atmosphere, Mars was tough to figure. There are areas which appear darker or lighter (these are called Albedo features); to an enthusiastic observer, it was easy to speculate of continents, oceans, or even straight-line canals.

Beset by the same optical illusions, many astronomers seconded Schiaparelli's observations. The maps of the day show a Mars riven with peculiar webs and lines–lines which successive high-resolution mapping of the planet have definitively shown do not exist. The mechanism that caused this illusion appears to be internal: faced with a shifting landscape of foggy forms, glimpsed at through simple lenses of glass through the refractive index of Earth's atmosphere, the human brain tends to impose order.

The persistence of belief in Martian canals is often attributed to a linguistic fluke, that the Italian canali, meaning "channel" (or watercourse, and not necessarily of unnatural origin), was mistranslated to the English "canal." I really love this narrative of language shaping reality, but unfortunately it's the astronomical equivalent of an urban legend. "Canal," in fact, was used in the earliest English accounts, and Schiaparelli made no move to correct the misunderstanding, if he was aware of it.

Still, astronomers ran with the idea. The Irish astronomer Charles E. Burton made beautiful sketches of the lines, and (according to an unsubstantiated Wikipedia entry) speculated that they were ley lines used by Martian sorcerers. The American Percival Lowell, who founded the Lowell Observatory in 1894, made the most committed speculations on the subject. Despite ramping scientific skepticism to the contrary, Lowell almost single-handedly popularized the notion of the canals as proof that the planet once sustained intelligent life. His drawings of the canals look like Italian Futurist masterworks or the spacey doodles of Joan Miró.

"That Mars is inhabited by beings of some sort of other we may consider as certain as it is uncertain what those beings may be."
– Percival Lowell

In his books (sample titles: Mars and its Canals, Mars as the Abode of Life), Lowell put forth a theory that the canals were visible traces of an dwindling civilization's attempts to tap the planet's polar icecaps. The late 19th century was a period of great canal-building on the home planet–the Suez and Panama Canals were both freshly dug at the end of the 1800s–and so the dreamy hypothesis that Schiaparelli's canali were irrigation canals made by intelligent beings resonated with the cultural imagination.

Later, Percival Lowell began to notice similar phenomena on Venus; simultaneously, as telescopes and astronomical technique developed, his theories were objectively discounted. More recent scholarship suggests that Lowell was merely observing projections of the vein structure of his own eyeball, a known nuisance among planetary observers using very high magnification. This would explain, among other things, the phenomenon's consistency across two far-flung planets in our Solar System.

Given the symbolic parallels between outer space and inner space in many cultures, the fact that Percival Lowell spent an entire career mapping the strucure of his own retinas while believing them to be interplanetary ruins is very nearly mystical.

As it turns out, there really are canali, or watercourses, on Mars–but that's just another marvelous instance of life imitating art. As for art imitating life, well, despite the fact that his scientific study was for nought, we can credit Lowell's inverted astronomy with the origin of a lasting trope within the science fiction of the early half of the 20th century. His "vision," if you will, of a dying Mars–and an ancient culture fighting to survive in its arid deserts–persisted in the works of Edgar Rice Burroughs, Robert Heinlein, and C.S. Lewis, to name only a few. One might even argue that Lowell's theories about water scarcity form the basis of a broader conceit about aliens coming to Earth to pillage our resources, in which case he is the unwitting progenitor of everything from The War of the Worlds to Mars Attacks.

But back to the canals: Ray Bradbury, in The Martian Chronicles, had them flow with poetic "green liquors" and "lavender wine" under the yellow sun. Later, Philip K. Dick would imagine despotic Water Workers' Unions controlling access to the little sustenance the Martian canals eked across the harsh Martian landscape. It's a broad spectrum, certainly, but many of the romantic associations we hold to Mars–the sense that it hangs in space like a ghost, a ruined sibling of Earth–are derived from these literary reveries, nearly all of which can be traced back to bad eyesight and illusions.

cevans Fri, 09/28/2012 - 17:31

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Giovanni Schiaparelli

Although it makes a good story to blame the appearance of canals on Mars on one man's bad eyesight, it doesn't reflect history accurately. Lowell was far from the only observer to see the canals, and maps with similar features were drawn by others: Schiaparelli, of course, but also Antoniadi (early in his career), Douglass, Pickering, Williams, and many others.

As Antoniadi showed over several decades of work with the Meudon refractor, the surface of Mars is covered with many small and low-contrast surface features. As human eyes view these features through the ever-changing atmosphere, they often perceive linear features running from one darkish spot to another -- even though no such linear features really exist. The human visual system apparently has a quirk for imposing some sort of order on the chaotic and ephemeral image.

It would be more fair to blame the human visual system for the many reports of Martian canals, not the bad eyesight of Percival Lowell alone.

On the other hand, Lowell's reports of canals on the disk of Venus cannot be attributed to this facet of the brain, as there are certainly no faint features to be seen in its atmosphere. So, if you wish to draw analogies between the tracks of blood vessels on the human retina and linear features seen on planetary disks, please restrict your discussion to Venus.

Hi Michael,

You make some great points, and I've edited the piece for clarity in the light of your comments. For what it's worth, I'm not pinning the belief in canals single-handedly on Lowell, just tracing a historical line from his eyesight to the forward-thinking "vision" of our cultural imagination of Mars. After all, it's Lowell's harebrained theories–that the "canals" he saw were signs of an intelligent, but dying, civilization–that fed the popular imagination, forming the basis of the fictional representation of Mars today.

Thanks again for your fine-toothed fact-checking.

There's no doubt that Lowell's ideas were both wrong and enormously influential, so your basic point stands, of course.

By the way, if you happen to have the chance to hold Lowell's books in your hands and read them, please do -- you'll find that they are beautiful examples of the bookmaker's art. The current prices for copies are in the high hundreds of dollars, and for good reason.

I do wish that more scientists had the time and the money that Lowell had, so that they could produce monographs on their own favorite topics.

Michael, if the handful of Lowell's illustrations of Mars that can be found online are any indicator, I'm certain his books are lovely!

On Curiosity and its Shadows

cevans — Sun, 05 Aug 2012 22:19:43 +0000

On Curiosity and its Shadows

The NASA Mars rover Curiosity just landed on Mars. Those of us who tuned in vicariously via NASA's live coverage watched as a roomful of tense engineers exploded, and heard their disembodied voices whispering and booming through the control room. Holy shit. We did it. Their headsets fell askew, they glad-handed one another, criss-crossing the room, and then, immobilized by a sudden hush as the news spread: We've got thumbnails.

Thumbnails. We watched as a tiny image formed, transmuted across the void of space and into this room. It was black and white, an indistinguishable gesture of light in a blur of dark pixels. The engineers cheered and held one another as they gazed upon this small, inauspicious sight. One man sobbed at his desk. Then another image came down the line, this time more resolved. We began to see the grain of the dust, the pebbles, the outline of the rover itself, 352 million miles and 14 minutes of delay away, struck against the Martian soil.

And so, as with so many missions before it, the narrative of our rover's discovery began with an acknowledgement of its own shadow.

NASA's older Martian rovers, Spirit and Opportunity, were both avid amateur photographers of their own shadows as well. In fact, such images have been part and parcel of the visual language of space history since the Soviet Union developed and launched the Venera probes in the early 1960s; which, beginning with Venera 9, were the first landers to send back images of another planet. Those pictures too, taken before the cameras were undone by the very atmosphere they hoped to document, were of light and shadows cast on rocks.

Rocks that looked for all the world like our rocks, light like our light, and shadows like our shadows, only cast on an alien world.

William Gibson writes that the moment we began sensing and recording with technology, our extended communal nervous system, the "absolute limits of the experiential world" were "in a very real and literal way...profoundly and amazingly altered, extended, changed." We no longer relied on the limited capacities of our individual memories, nor did we quite fully trust the bounded senses of our apparatus; free to back ourselves up and reach ourselves further outward, we extended our reach. We also loosened the definition of "we," allowing our tools to become part of us in subtle ways. Now, closer and closer to the machine, we share a "largely invisible, all-ecompassing embrace."

This means: we can't go to Mars and see what it looks like for ourselves. Not yet, anyway. So instead we have sent this robot, this laboratory, this sentry of extended sense organs for the human race, ahead of us. I find it profoundly moving, not only because something inconceivable has been accomplished, but because we--that room full high-fiving tinkerers, and us plebeians too--can look at Curiosity's shadow and understand, without hesitation, that it's our own.

cevans Sun, 08/05/2012 - 18:19

Tags

The intersection of poetry and science Wonderful

The image that came down first, although apparently dull, very probably captured in the impact dust cloud of the skycrane. I'm sure there's another analogy in that.

What amazes me is that sunlight on Mars appears as bright--or nearly as bright--as sunlight on Earth, even though Mars is so much further from the Sun. I would have expected there to be less of a shadow, and that the atmosphere would be darker.

NASA rocks!

why not send one rover like curiosity to the moon and prove that the men of the apollo project got there?

Would'nt be prudent to land next rover at the equator of Mars, where the climate could be tropical like earth. Mre organisms could have survived there in ancient Mars !!

@MEL: Because NASA doesn't actually care what conspiracy theorists say, and their allegations don't deserve the dignity of a response. Sending another Curiosity-level rover to the Moon just to try to convince a few naysayers that they really did it would be a massive waste of time and money, especially since it won't convince them anyway. NASA scientists know what they did, and they're the ones who use this information. Rovers are for learning new things, not winning arguments.

I hope one day people can live on Mars!

To Mel - it's all about the money and getting funding. You wont get much funding going back to the moon (or there first the first time if we havent...according to some theorist). It's all about Mars now. NASA were scaling back missions before this last successful landing on Mars. They're flying high now and there's several new missions to Mars planned in the next few years only thanks to the success of this lander. If this would have failed then they'd probably go back to the moon as that's the only thing they'd be able to afford.

there's nothing like our planet.

First off, I love the fact you write about this topics claire.
2nd off I was lucky enough to be at NASA/JPL next to the control room when this happened and I'll tell you that the pure excitement, and reward for the engineers is like no other communal joyful moment I have witnessed. The whole week at work, we would randomly stop to watch "Space News" and get our daily scoop of curiosity. I just wanted to share that since you are so heavily interested in the matter.

I truly felt like I was in a pre-star trek era when she landed.

Over and Out
www.phillipschristopher.com

best ever achievement (yet) for human-kind...but l prefer to live in our plenet earth....tell me..where the hell is waikiki beach???ipanema rio???great wall etc.etc.etc???

Mars is Freeze Dried, a wee bit chilly .

Bswerdloff
subject Curiosity on Mars
In looking at my latest National Geographic Magazine--and
remembering that famous event at Roswell---I was
instantly wondering Who is cleaning the wheels on
Curiosity They sure did a good job.

Curiosity's wheels are specially designed to spell out JPL over and over in the dust in Morse code.