Gliese 581g: the first Earth-like habitable planet found around another star!

This is a big day. Mark the date Sep 29,2010 - for the history books!

Space.com news link is here, and here is a link to the original paper announcing this discovery.

Over the next 3 to 10 years (thanks to Kepler and improving Earth optics), we should expect to hear more details about this one, and 100s more like this one, but with lots of variations (e.g. dwarf habitable moons- which CAN be easier to detect, by looking at secondary wobbles of the primary planet, but this is the first real one with just the right temperature, mass and everything.

Now we can finally start pointing our SETI telescopes in the right direction :-) Confirmation of life-signs might take another few years, using spectrometer and interferometer combinations, but the fact that Gliese 581g (look forward to a more personal, official name soon for this first habitable planet :-)), is smack in the middle of Gliese 581's habitable zone is awesome- no debates about habitability on this one, only the question about how much water is going to be there. That would determine whether it's a water-world with higher phase ice at the bottom of its oceans that completely block continental minerals from mixing, so that it turns out to be a water desert (also see http://www.egy.org/files/cloutier.pdf), and where water dominates so much that life occurs in islands and pockets of minerals left over by asteorid impacts an dusts only), or whether it's an Earthly desert (where life has adapted to dewdrops and oases). In either case it would be awesome, and leave a lot of possibilities for a complex biosphere, and we should soon know which of the two scenarios is the real one, when we get measurements of this planet's atmosphere content (how much water vapor). If it has less water, that is probably better for this planet, as too much water can be a very big problem for advanced life to evolve in the 7 to 11 billion years current age for this planet. However, note that since the parent Sun can live virtually forever (this star is 50 times dimmer-than-our-sun red dwarf even though it has 30% of Sun's mass, which gives it a very long life), even if there is too much water, eventually enough water-loss because of the solar wind would cause Gliese 581g to have just the right amount of water eventually to have continents protruding out. I am really hoping it has some water though :-) and conditions point to that being the case , when combined with the fact that it is much heavier than Earth, and is smack in the middle of the habitable zone.

Regarding verification of how much water it has, and the atmospheric composition (which would hugely increase our confidence in imagining specific forms of life there), I predict that the discovery of this planet is going to motivate lot of smart astronomer-engineers to come up with ways to measure the atmosphere ASAP, even if TPF-I does not launch for another decade or two. I also believe that these discoveries, as they mount over the next 2-5 years, will force the urgency in funding for such a telescope, just like the Mars exploration program got a huge boost from the discovery of recent volcanism, rivers, oceans on Mars, and even more- the recent discovery of liquid water, water-runoffs, and methane on Mars.