when will we know...

I say screw patience.

What do we want? More planets!

When do we want them? NOW!!

;)

Perhaps you would not violate the embargoes by mentioning the teams involved in the embargoed results.

Perhaps not. If you are referring to the OGLE result then,
as I understood it, the result was not submitted or in press with an embargoed organization, and the speaker did not request the result be kept secret.
It was an open meeting, with press present.

I know the result is preliminary, I did not identify the object or any quantitative aspects of it.

But, you guys send out alerts to a large number of people when stuff happens - you can't expect the existence of an interesting event to be a secret.

If you mean any of the other results, I did not identify indirectly any of the formally embargoed results - those are one Nature in press, one Science submitted, and two where the presenter asked specifically the results not be mentioned pending confirmation.

If people announce results then I presume they may be discussed unless specifically requested not to - there were 200 people in the room.

Thanks, Steinn.

But the "OGLE" result was the one I already know about, since I am the lead author on one of the two papers on this event. The lead group is actually not OGLE, but MicroFUN, although the name of the planets is derived from the microlensing event name, which starts with OGLE.

I was wondering if you could say which groups had the Nature paper in press, and the paper submitted to science. The embargoes are intended to keep the news out of the press prior to publication, so I think that it shouldn't be a problem to announce which groups are involved.

Oh sure - there is a french observatory group that has a planet detected around a new class of star - one which has not had planets seen around it before; the lead author name is in my notes, which are in my suitcase, so I can't tell you right now. That is the Nature paper, should be out any week now.

The Science paper is from Carnegie DTM. Spitzer result.

Sorry about not mentioning MicroFUN - I had the OGLE tag in my notes, and I was not sure what linear combination of the microlensing collaborations was the team for this object.
Which is very cool by the way.

PS: David - I was worried you were annoyed I had mentioned the MicroFUN OGLE detection and "leaked" the result - I try hard not to reveal confidential info and Scott had presented
the results as an "announcement" so I thought it was ok to mention publicly - of all the results out there, your group is one that just cannot be scooped by other teams!

It is tricky sometime - eg I mentioned the TrES-4 transit, because that was also formally announced by someone from TrES, but the other new transit detections I didn't mention because they were talked about but not announced by team members.

Planets around a new type of star not previously known to host planets? SpT A maybe even O type stars? Can't be Wolf Rayet stars or Black Holes or can it? hmmm...and then these new transit planets...and that about Proxima in another entry...sounds like a few interesting weeks ahead ;)

I've a question for you guys here.

I had a thought that without plate tectonics, an Earth-sized world does not have the regular vulcanism that the Earth has. Rather, it has a global resurfacing event every 500 million years or so, creating a Venus-like environment.

It is also thought that the impact that made the moon also created the conditions by which plate tectonics could take place.

In otherwords, without the large moon, you have no plate tectonics. Without plate tectonics, instead of an Earth, you get a Venus, instead.

This is the part of the Rare Earth hypothesis that I have read about.

Has there been any discussion about this among your mates in this field? Is there any possibility in the near future of being able to characterize any Earth-sized planets detected around near-by stars, to see if they really are "Earths" and not "Venuses"?

Dear Kurt9,
Sometimes, you have to be a little careful with books written by scientists, because there is no peer review for books unlike science journals. Also, books filled with speculation tend to sell a bit better, since they can present more "new" results. Much of the astronomy and biology presented Rare Earth is rank speculation, and I suspect that the same is true for the geology. The prevailing view seems to be that Venus doesn't have plate tectonics, but it might be difficult to recognize the geological signatures of plate tectonics when the surface temperature is 750K. There have been a number of reasons suggested for the lack of plate tectonics on Venus including the lack of a large moon and the lack of water (which is carried into the mantel in subduction zones). In contrast, Mars is thought to lack both plate tectonics and current vulcanism due to the lack of a sufficient heat source (radioactive decays in the interior).

The main difference between Venus and Earth is thought to be the lack of water on Venus. This is thought to be caused by the additional solar heating that results in water vapor rising high in the atmosphere where it can be split into H2 and oxygen by UV radiation. The H2 then evaporates off into space, and this eventually removes the Hydrogen. Because the Sun's brightness is steadily increasing, the same thing is predicted to occur on Earth in about 500 million years (unless we do something about it).

If NASA ever decides that it wants to fly the Terrestrial Planet Finder (TPF) mission, it would be able to distinguish between extrasolar Earths and Venuses via spectra of the planetary atmospheres. However, the latest word from NASA HQ suggests that serious work on TPF may not resume until 2020, so we may have to wait until 2025 or 2030 for such results.

David,

My understanding of Venus is that it has a relatively "new" surface.

http://www.agu.org/pubs/crossref/1994/94JE00388.shtml

http://www.harmonicamundi.org/HGS/atmos_proj/format.html

I have also heard that Venus radiates 40 times more energy than it absorbes from the sun. I don't know if this is true or not because I cannot find the reference for this. However, if this is true, the global resurfacing events could account for this heat.

in any case, I think the issue of Venus is a relevant factor in the occurances of "Earth-like worlds through out the galaxy.

Mars also has unusual features that suggest "attempted" partial global resurfacing. The unusual smoothness and lack of craters in the northern hemisphere, when the souther hemisphere is pock-marked with craters. If the northern hemisphere was an ocean, then there had to have been an atmosphere (and climate) that would erase the craters in the southern hemisphere as well.

Also, the Tharsis bulge. This also looks like what could have been a huge partial resurfacing event, but the planet lacked the internal heat to make the bulge actually break open into a resurfacing event. Also, all of those huge volcanoes (like Olympus Mons and what not) are located on the Tharsis bulge.

I'm not a scientists, so my thinking could be totally wrong here. But it looks like both Venus and Mars have had resurfacing events in the past and the Earth has not. Global resurfacing events, if they are real, are no doubt bad for climate and life. I cannot help but think that the correlation here is that the Earth has plate tectonics and the other two do not.

I agree with the postings on here that the Rare Earth hypothesis is turning out wrong with regards to available planets around the nearby stars. However, I consider the large moon/plate tectonics issue to the be central part of the Rare Earth Hypothesis. This parts has yet to be confirmed or disproven.

David,

The other part of the large moon/plate tectonics issue of Rare Earth is the giant impact theory of how the moon formed in the first place. Is there any modeling or direct evidence indicating what the pre-impact Earth was like? I heard from a TV program that it was a waterworld, with oceans 15-20 miles deep. Again, I cannot find a reference for this.

If Venus's lack of plate tectonics is, indeed, due to a lack of water (loss via the mechanism that you describe), then it would seem that as long as the planet is far enough out from the sun (but not TOO far out) that it should be OK and will become an "Earth".

Like you, I am not a fan of Rare Earth hypothesis. However, it does set a pessimistic lower limit on the availability of Earth-like worlds and is useful from this standpoint alone.

Kurt,
We certainly don't know that the Earth had oceans 15-20 miles deep before the impact that made the moon. I'm not sure that the earth would have been cool enough to have much liquid water then.

Also, this "resurfacing" refers to covering impact craters, and the Earth's weather certainly manages to do that more efficiently than whatever did this on Mars of Venus. So, resurfacing can actually be good for or even caused by life.