Is science drawing closer to an alien world?

Paris (AFP) ^ | July 24, 2015 | By Mariette LE ROUX

[kjam22]

Yep.... You know... I once had a job that I thought was completely irrelevant and unimportant. But nothing like this. Can you imagine going to work everyday to look for planets that are 33,000 travel time years away, and trying to figure out if they are made of rocks or gas?

[exDemMom]

Can you imagine going to work everyday to look for planets that are 33,000 travel time years away, and trying to figure out if they are made of rocks or gas?

I can assure you that the people doing that work do not think that there is anything irrelevant or unimportant about it. They probably grew up stargazing and watching shows of space exploration like Star Trek and Lost in Space. For them, going to work and studying the sky is the next best thing to living those childhood fantasies--but in a more adult manner. It is a dream come true.

Although I ended up following a career in the biological sciences, I could see myself being perfectly happy as an astronomer, searching the sky for new objects and getting excited with every new discovery.

[exDemMom]

Actually, life as we know it isn’t a big caveat, not if we are talking about an organism with a larger capacity brain capable of intelligent thought. The larger brain to body mass requires diverse and abundant food sources driving the energy requirements to direct a higher percentage of fuel to the brain. That drives a whole raft of requirements on the host planet.

That was not quite what I was talking about. I was referring to the fact that every living organism on this planet has a common biology. We all use DNA and RNA as carriers of genetic information, with the same nucleotides encoding protein sequences and genetic control elements. We all use proteins made up of the same 21 amino acids (or variants thereof). The fact that all life on this planet has this biochemical similarity does not mean that all life on other planets would be constrained to the same biochemistry. We simply do not know, since our sample size of planets supporting life is n=1, as is our sample size of biochemical parameters of living organisms.

Without really knowing the parameters within which life can exist--which we can only determine through finding and analyzing other life-bearing planets--we have no idea whether we are excluding potential life-bearing planets from consideration by constraining the search to "earth-like" planets. It is almost certainly a moot point, in any case--the time required to travel even to just the nearest star makes any real space exploration impossible.