Originally posted by lausey
Good point, and if life is discovered just 20 light years away, coincidences aside, that will suggest that this galaxy is quite densely populated with life.
It will take finding another planet with life in close proximity to confirm that further.
One big problem: dwarf stars are not benign little guys. Our sun is in the top 5% of size in the galaxy numerically speaking. Our sun is very benign, it blows its top every now and then but Earth's magnetic field is enough to shield all but the most energetic blowups on the surface of the sun.
This star, Gliese 581, is a dwarf and its planet in the goldilocks zone, but there is a big caveat, such stars have much more active surfaces than our own sun and they regularly blow their tops in much more spectacular fashion than our sun. The problem with that is the planet being much closer is also more likely to have been hit multiple times by the furious radiation streaming off the star in these episodes.
This means that planet would have been sterilized many times in its past and would be unlikely to have the time to develop any kind of advanced life. There may be microbes and such but with Gliese blowing its top every now and then it would be reset to zero every time and have to start up fresh after each episode.
Of course that is all speculation now, since we have no surface images and such but the main thing we can say is in a star system so close we have found evidence of a goldilocks world. That alone says there must be others orbiting benign stars like our sun. If I was making the first expedition to another star, even though Gliese is so close, I would aim for Alpha Centauri, you get three stars for one trip and two of them are nice mild stars like the sun and it's one fifth the distance.
Has anyone heard estimates of the surface gravity of this newly found planet?