KennyR wrote:
Blobrana wrote:
i`ve got a feeling that mars is crawling with underground lifeforms...er, like the earth...
Well, they obviously don't use sunlight, or Mars would be green. So they would have to live off warmth and sulphides produced by volcanism. Trouble is, unlike Earth, Mars cooled out a long time ago. No more volcanism. So where would they get their energy from?
Organisms don't necessarily have to live off any warmth. Ambient temperatures that don't stop the essential cellular processes from taking place (and possibly creating their own metabolic warmth if need be) should be sufficient.
Photosynthesising lifeforms wouldn't have to be green. If Martian plants/algae/whatever use a chlorophyll-like isozym for photosynthesis it would probably be adapted to Martian light, together with the plants' pigmentation like deep-sea algae, cyanobacteria et c. How long has the Martian sky had the same colour that we see today? An evolutionary significant amount of time? And single bacteria-sized organisms here and there don't really have any discernible colour.
We're still talking about hypothetical lifeforms in a largely unknown environment on another planet, and yet we're applying rather specific Earth biology on our speculations...
And how should we define "life" on Mars to begin with? Is a self replicating nucleic acid life?
