NASA's Kepler Telescope Discovers First Earth-Size Planet in 'Habitable Zone'

[Trakar]

Then there is that moon with liquid water under ice...

There are more things, Horatio.

I get that proving liquid water is problematic. However, the Goldylocks zone is pretty well-defined. And even if we can't prove anything on this planet, it is valuable proof of concept--we can find planets of the right size, in the right place. Now we need to find the right planets. Simply finding this planet is proof that we can do what we set out to do. To say what you did above when we have literally only just begun the search is far too dismissive of the find. Believe me, crap finds are VERY important at the early stages of explorations, as they allow one to refine one's search parameters and to learn what to look for. We've found the eroded scrap of bone in the wash, now we just need to follow it up-slope.

Liquid surface water was one of many early approximate markers for life when it was one of the only easy markers that we could see between the pervasive life dominating our planet and the apparent sterility of all the other planet's in our system. We have learned much in the last six decades, and evidence of ET life seems much more rare now than it did then.

 

[Corsair 115]

We have learned much in the last six decades, and evidence of ET life seems much more rare now than it did then.

I would add the distinction of what kind of ET life. There is a world of difference between bacteria and elephants. The former, if Earth is any indication, are incredibly resilient and seem able to exist in a large range of environmental conditions. The latter, on the other hand, are fragile, can exist within only a narrow environmental range, and took a long, long time to appear on the Earth.

In other words, bacterial life may be very common in the universe but large, complex creatures may not be.

 

[Trakar]

I would add the distinction of what kind of ET life. There is a world of difference between bacteria and elephants. The former, if Earth is any indication, are incredibly resilient and seem able to exist in a large range of environmental conditions. The latter, on the other hand, are fragile, can exist within only a narrow environmental range, and took a long, long time to appear on the Earth.

In other words, bacterial life may be very common in the universe but large, complex creatures may not be.

There seems to be a very distinct difference between the environmental conditions that existing life can gradually adapt to survive and even thrive within and the mysterious but apparently specific conditions required to spawn life from non-life.

There are undoubtedly innumerable worlds which might prove fertile to introduced life, but I know of nothing indicating that the precise conditions necessary to initially generate life are anything but rare and uncommon.

 

[quadraginta]

<snip>
There are undoubtedly innumerable worlds which might prove fertile to introduced life, but I know of nothing indicating that the precise conditions necessary to initially generate life are anything but rare and uncommon.

It isn't clear to me that actual evidence they are rare and uncommon is substantially better.

We've only done a very llttle bit of looking by any objective standard. All the rest is surmise and conjecture.

Perhaps the understanding of "rare" is at issue. It might be something of a moving target. Something can be rare but still happen a lot when the sample size is sufficiently large. We have a really big sample size to work with here.

The odds of human beings evolving were, at one time at least, vanishingly small, but here we are. It almost seems like a sort of exceptionalism to conclude that something like it is unlikely to happen again.

 

[Corsair 115]

The odds of human beings evolving were, at one time at least, vanishingly small, but here we are. It almost seems like a sort of exceptionalism to conclude that something like it is unlikely to happen again.

The question is the frequency of that. There seems to be the idea (no doubt fueled by such things as Star Trek and Star Wars) that each galaxy must be teeming with complex, intelligent life forms. There is no reason to assume that is true. And even if it isn't true that hardly makes the universe devoid of such complex, intelligent beings. At the paltry average rate of just one complex, intelligent species per galaxy, with something like 100 billion galaxies in the universe that'd mean there are 100 billion intelligent races. That's a huge amount.

 

[Trakar]

It isn't clear to me that actual evidence they are rare and uncommon is substantially better.

We've only done a very llttle bit of looking by any objective standard. All the rest is surmise and conjecture.

Perhaps the understanding of "rare" is at issue. It might be something of a moving target. Something can be rare but still happen a lot when the sample size is sufficiently large. We have a really big sample size to work with here.

The odds of human beings evolving were, at one time at least, vanishingly small, but here we are. It almost seems like a sort of exceptionalism to conclude that something like it is unlikely to happen again.

I see nothing that I would argue against, or even quibble with in your statements, which leaves me in an exceedingly rare and uncommon personal position of complete agreement on this issue!

 

[Trakar]

The question is the frequency of that. There seems to be the idea (no doubt fueled by such things as Star Trek and Star Wars) that each galaxy must be teeming with complex, intelligent life forms. There is no reason to assume that is true. And even if it isn't true that hardly makes the universe devoid of such complex, intelligent beings. At the paltry average rate of just one complex, intelligent species per galaxy, with something like 100 billion galaxies in the universe that'd mean there are 100 billion intelligent races. That's a huge amount.

Part of the problem we face at this point in history is that our understanding of abiogenesis with respect to our own particular form of life (yet alone understandings of whether or not other forms of life are even possible) are both exceedingly crude and incomplete. So while our type of carbon life may indeed be sparse in this neighborhood, plasma faeries that live in stellar coronae and two-dimension crystallines that swarm across the crusts of neutron stars may well be both common and frequent for their environments. Such speculations however, are not adequate stand-ins for evidences. So we go with what we can evidence.