05 Oct 10
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20 light years is very close in astronomical terms.
I think Dr. Vogt's personal view that the probability of life on the planet being close to 100% is rather optimistic. You can have many planets capable of sustaining life, but the odds of it occurring on these planets is very small. However, I am convinced that there will certainly be life on other planets, just the chance of it being this close is unlikely.
05 Oct 10
Originally posted by lauseyAnd I think the chance of life occurring is totally unknown. We have only one sample to go on and that is really not very good for doing statistics.
I think Dr. Vogt's personal view that the probability of life on the planet being close to 100% is rather optimistic. You can have many planets capable of sustaining life, but the odds of it occurring on these planets is very small. However, I am convinced that there will certainly be life on other planets, just the chance of it being this close is unlikely.
05 Oct 10
Originally posted by twhiteheadWe can actually say that life occurring is everything but impossible. We are life.
And I think the chance of life occurring is totally unknown. We have only one sample to go on and that is really not very good for doing statistics.
If we didn't have any kind of life on Earth, we couldn't say anything...
05 Oct 10
Originally posted by highdrawI often wondered if tendency to form a religion is just a freak accidental side-effect of the evolution of the human brain unlikely or even virtually impossible to evolve in the intellect of an alien from another world?
I wonder if there is life there....do they have the same bible?....whoa...I'd be a believer then!
And could the same thing be said about a sense of humour?
Or having a concept of “morally right and wrong”?
Or having an appreciation of music and art?
And could one or more of these alien species evolve with something mental 'like' the above ( 'like' in the sense of being extremely unlikely evolutionary outcome of their intellect ) but something that we would not understand nor have! (Just like an alien that has no humour will never understand a human joke etc )
06 Oct 10
Originally posted by twhiteheadGood 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.
And I think the chance of life occurring is totally unknown. We have only one sample to go on and that is really not very good for doing statistics.
It will take finding another planet with life in close proximity to confirm that further.
06 Oct 10
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Originally posted by lauseyOne 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.
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.
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?
06 Oct 10
Originally posted by sonhouseI'm not so sure that stable planetary orbits suitable for life is impossible in the Alpha Centauri system.
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.
Two sunlike stars orbiting eachother at a distance from eachother of between 11 and 35 AU in an elliptic orbit, giving an orbital period of 80 years. A planet of the size of Earth, orbiting one of the stars at 1 AU, will be disturbed over the time of the other star, so life (as we know it) might be hard to evolve.
06 Oct 10
Originally posted by FabianFnasLife, as we know it, is a key point as well. It doesn't rule out the possibility of life vastly different from ours from evolving in very different environments.
I'm not so sure that stable planetary orbits suitable for life is impossible in the Alpha Centauri system.
Two sunlike stars orbiting eachother at a distance from eachother of between 11 and 35 AU in an elliptic orbit, giving an orbital period of 80 years. A planet of the size of Earth, orbiting one of the stars at 1 AU, will be disturbed over the time of the other star, so life (as we know it) might be hard to evolve.
Of course, life has a very good chance of evolving very differently to ours, even on a planet similar to our own.