New habitable Planet found
By Joel Achenbach | September 30, 2010; 8:07 AM ET on the Washington Post
Finally, astronomers have found a planet in the Goldilocks position — not too hot, not too cold, not too big, not too eccentric, not too young, not too stupid, not too self-involved, not too prone to staying out until 3 a.m. with unsavory characters, etc. A nice little planet in a good neighborhood. This is pretty huge, and congrats to Vogt and Butler, the astronomers, for teasing this thing out of the data.
But can I just point out that there’s a difference between “habitable” and “somewhere you, or anyone else, or any creature, would actually want to live.”
This would not be like Earth. For one thing the sun would always be on the horizon, just hanging out. (You call it a sunset, but I, the optimist, say it’s a sunrise.)
We don’t know the atmospheric chemistry (assuming it has an atmosphere). We don’t know if it has plate tectonics to recycle the carbon. We don’t know if it has water (though wouldn’t it, just from comets?).
As I understand planet-hunting technology, it’s not possible to get a spectrum of this planet to learn anything about it directly. We see it entirely though Doppler shifts in the light of the parent star. It’s like backpacks, shoes and empty lunch bags in the foyer: You know the kids are home from school even though you do not actually see them.
The biggest thing we don’t know is how life originates. That’s a question you can argue round or square. Seems to me it emerges naturally from the chemistry of the universe, but Paul Davies thinks not. (See my discussion of Davies vs. Morowitz.)
The fact that Gliese 581g is relatively close and was found relatively soon in the process does suggest strongly that the galaxy is lousy with Goldilocks planets.
So it’s a good day for the Sagan scenario. If life is common (big if), and habitable planets are common, then you’re looking at night into an extremely biological universe.
More at Wikipedia