Astronomy
esiegel | February 4, 2010What we know about Pluto today could fit on the back of a postage stamp. -Colleen Hartman
Part of the joy of astronomy is, every once in a while, you just get an astoundingly beautiful new picture or video of a foreign planet, star, galaxy or cluster. Pluto, the most distant planet, is among the most elusive.
This picture above was snapped by the Hubble Space Telescope about a decade ago, and shows us Pluto (center) with its large moon Charon and its two smaller moons, Nix and Hydra.
It's pretty difficult to get better resolution pictures of that planet because Pluto is both so far away and…
esiegel | February 3, 2010Nobody can go back and start a new beginning, but anyone can start today and make a new ending. -Maria Robinson
In parts one and two, we covered the very beginning of the Universe as we know it. Specifically, we talked about inflation, which is the process that sets up the Big Bang. Inflation -- to recap -- expands the Universe exponentially fast, driving the matter density to zero and stretching the Universe flat like a balloon getting blown up supremely fast.
But inflation ends, and when it does, all of that stored (i.e., potential) energy that was being used to expand the Universe now…
milhayser | February 1, 2010
On Starts With A Bang, Ethan Siegel presents us with an interstellar mystery. As the single brightest star in the sky, Sirius has been well-known since ancient times. But while Sirius is unmistakably blue, several historical records describe Sirius as red. Two thousand years is not enough time for a normal star to change color, so what could have happened? Simple human error? Changing atmospheric conditions? A roving Bok Globule? Or does Sirius's companion dwarf star suggest an even more incredible explanation? In a separate post, Ethan says he won't miss NASA's Constellation program…
esiegel | February 1, 2010I'm as mad as hell, and I'm not going to take this anymore! -Howard Beale
Let me tell you a little story. Nine years ago, I was living in California, and I had a car accident. The damage to my car was pretty bad; the first estimate I got said that it would take about $3800 to fix it, more than the entire value of my (then) 11-year-old Volkswagen, and about one-and-a-half months' salary for me at the time.
What I decided to do was -- I hope -- what any reasonable person would do. I had just enough repair work done so that the car was drivable, and then I took it around to different shops. Why…
esiegel | January 28, 2010We shall not cease from exploration and the end of all our exploring will be to arrive where we started... and know the place for the first time. -T.S. Eliot
Yesterday, President Obama delivered his first State of the Union Address, and talked about a number of things that ranged from inspiring to disappointing. But one thing that didn't make it into the address was the rumor that NASA's Constellation program (including the Ares Rocket designed to launch crews) will lose their government funding.
(Please note: what follows is my opinion, and I take responsibility for it.) If this actually…
esiegel | January 27, 2010Blue flower, red thorns! Blue flower, red thorns! Blue flower, red thorns! Oh, this would be so much easier if I wasn't color-blind! -Donkey, from Shrek
Earlier this week, I introduced you to the Red Controversy, the observations recorded around 2000 years ago in Europe asserting that the star, Sirius, appeared red.
Now, taking a look at Sirius today, it is clearly not red:
And, based on what we know about stars, they don't change color on timescales that quickly. Many of you put forth some very good ideas, and I thank you for the comments. In fact, the most common one was the very first…
esiegel | January 25, 2010Artists can color the sky red because they know it's blue. Those of us who aren't artists must color things the way they really are or people might think we're stupid.
-Jules Feiffer
Last semester, I was teaching my introduction to astronomy class, and part of the coursework was that each student had to choose a unique research topic and write a research paper based on that topic. Topics varied from cosmology to relativity to the space program to individual planets, but one choice captivated me so much that I bring my version of it to you now.
Astronomy was, arguably, the very first science…
grrlscientist | January 25, 2010tags: astronomy, cosmology, black obelisks, Dwarf Galaxy Dance, formation of dwarf galaxies, cold dark matter model, NPG, peer-reviewed research, NATURE, 10.1038/nature08640, streaming video
This beautiful animation shows how exploding stars are a key force in shaping dwarf galaxies. Fabio Governato and colleagues present computer simulations that appear to have solved a longstanding problem in cosmology -- namely, how the standard cold dark matter model of galaxy formation can give rise to the dwarf galaxies we see around us.
DOI: 10.1038/nature08640.
esiegel | January 24, 2010There are plenty of examples in the music world where a cover of a song is strikingly different from the original and still interesting. Take the song You Spin Me Round, which cracked the top 5 all over Europe and North America when Dead or Alive released it. (Click for video.) 15 years later, Dope released a cover of the song in a completely different style, with an incredibly different feel. Take a listen:
It's a pretty good cover. It's interesting to listen to, it's decidedly different from the original, and it's still instantly recognizable. But by time I get to the end of the…
grrlscientist | January 23, 2010tags: Galactic Center of Milky Way Rises over Texas Star Party, astronomy, science, stars, Milky Way, streaming video
This fascinating video is a time lapse video of night sky as it passes over the 2009 Texas Star Party in Fort Davis, Texas. In this video, you will see the bright galactic core of the Milky Way crossing the Texas sky. Images taken with 15mm fisheye lens.
esiegel | January 20, 2010I'm always happy to receive questions from those of you interested enough to ask them, and every once in a while one of them feels just right to write up an article about it. Today's comes from Brad Walker, who asks about the inside of gas giants. Specifically,
The question pertains to the insides of gas giants like Jupiter... My question is, supposing Jupiter is made of Metallic Hydrogen, and it was dragged close enough to the sun that its atmosphere evaporated, what would be left? How would it go from a very strange non-terrestrial core to a rocky body like CoRoT-7b? Why wouldn't the…
esiegel | January 18, 2010There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.
There is another theory which states that this has already happened. -Douglas Adams
We started off our series on The Greatest Story Ever Told by talking about inflation, or a period when the Universe was expanding exponentially. We see plenty of evidence that inflation happened from looking at the geometry of the Universe (it looks like it was stretched flat),
at the fact that the…
catdynamics | January 7, 2010The primary reason to go to the big annual society meetings is, of course
the hot science results
networking for jobs
schmoozing with your peeps
The Swag!
Yes, that is why we go.
The NASA Space Calendars, the Hubble Mission buttons, the institutional logo USB sticks, the 3-D bookmarks, and, of course, the legendary High Energy Astrophysics Red and Black pens.
But each year there are one or two inspired surprise original Swag.
Who can forget the Lockheed Lunar Stress Ball? The foam space shuttle?
The photometrically accurate B,V,R ruler set?
This year the fancy Swag was definitely the…
esiegel | January 6, 2010The Sun stood still and the Moon stayed -- and hastened not to go down about a whole day! -Joshua 10:12-13
Did you have a good New Year's Eve? Did you enjoy not just the fireworks and champagne, but also the Blue Moon (2nd full Moon of the month) that was out that night?
Were you in a fortunate enough part of the world that you not only saw the full Moon, but also managed to see the partial lunar eclipse that happened?
How this happened is pretty simple: the full Moon is always on the opposite side of the Earth from the Sun. When the side of the Moon that's lit up faces Earth, we see it as…
catdynamics | January 6, 2010more invaluable science nuggets and pretty pictures
The Galileoscope is a very cheap but functional 50mm astronomical refractor kit for introducing kids to optical observing; NB PRICE GOES UP NEXT WEEK!
They can also be donated - through an online click.
But, now Ric and Jean Edelman of Edelman Financial Services have donated $250,000 to the AAS to buy and distribute 15,000 Galileoscopes for distribution to teachers around the US for use in classroom.
Nice one.
Hm. Y'know Goldman Sachs could go a long way towards repairing their public image with a token $250,000,000 donation towards a…
catdynamics | January 5, 2010NASA Administrator Charles Bolden addressed a packed room filled with anxious astronomers at lunch today.
It was interesting, both in what he said and in what was omitted.
I'll get to actual science at the AAS Real Soon Now , so more politics in the meantime.
Bolden's talk was primarily a scripted speech, and he acknowledged as much.
There were no announcements of new initiatives, mission commitments or statements on funding - evidently the White House has not yet settled on a plan for NASA, in particular how to handle "Exploration" - ie human spaceflight.
The preamble anecdote on HST…
catdynamics | January 4, 2010liveblogging the AAS...
It is freezing in DC, but at the Marriott hotel across from the National Zoo the action is hot and heavy as 3000+ astronomers swarm to the annual meeting of the American Astronomical Society.
This is for the 7 astronomers who phoned it in, literally in one case, you know who you are.
Or, in case you got stuck in the exhibit hall lobby at 9:17 this morning and never found your way out of the basement again. Hope the WiFi signal is holding up down there.
There is a flurry of new results, though through some freudian mishap I just typed "flurry on few results" instead…
rallain | January 3, 2010Wow. In xkcd 681 comic, there is an impressive illustration of the common term "gravity well". Here is a small part of that large image:
I can't resist. I must talk about this awesome illustration. My goal for this post is to help someone understand that comic (although the comic itself does a pretty good job).
Energy
Energy is the key here. Here, I will talk about two types of energy - kinetic energy and field energy. In this case, kinetic energy is basically just the energy associated with something moving. Field energy is the energy stored in the gravitational field. You could…
esiegel | December 31, 2009Blue Moon
You knew just what I was there for
You heard me saying a prayer for
Someone I really could care for... -Richard Rodgers & Lorenz Hart
Tonight is the last night of 2009, there's a full Moon, there's a sliver of a partial lunar eclipse, and it's the second full Moon this month.
Q: Does having two full Moons in a month make it a Blue Moon?
A: In our modern times, yes, that's what we use that colloquialism to mean. The phrase "Blue Moon" is much older than that, dating back to at least 1528, where a pamphlet attacking the dogmatism of the church states:
Yf they say the mone is…
rallain | December 30, 2009Some time ago, I wrote about the awesome things the Greeks did in astronomy. Basically they calculated the size of the Earth, distance and size of the moon and distance and size of the sun. The value obtained for the distance to the sun was a bit off, but still a bang up job if you ask me. (where bang-up is meant as a good thing) If the greeks were in my introductory physics lab, they would need to include uncertainties with their measurements. What would the uncertainty in the final value look like?
In my introductory physics lab course, I have students measure things and estimate the…