Space theorist posits unusual life on Mars: San Francisco Chronicle

[Ivan Seeking]

Monterey -- The planet Mars may well have been the scene of the solar system's "second genesis," where forms of life vastly different from Earth's emerged deep beneath the Martian surface billions of years ago, a leading space scientist proposed Wednesday.

http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2003/09/04/MN303153.DTL

 

[The Opiner]

I was a little surprised by the last sentence in this article: "This would show us immediately that genesis is easy everywhere".

To me this seems like a stretch. As far as I understand it, life, especially complex life, is probably rare in the universe – possibly exceedingly so. Its presence is apparently constrained by, among other things, the need for ample chemical materials of the right kind to be present; available water; a suitable substrate; a planetary mass sufficient to retain an atmosphere of moderate depth; an acceptable sun to planet distance to maintain an acceptable climate; a stable, relatively circular planetary orbit; a sun of moderate mass to generate a steady source of radiant energy with a spectral distribution that peaks in the visual range and a sufficient timeline for requisite physical and evolutionary process to occur.

Plus, it may be telling that in all the years since the Very Large Array (VLA) of radio-monitors has been listening for civilization-signature radio waves across the heavens we still haven't picked up anything (at least as far as the general population knows).

 

[FZ+]

I spy a little problem... How far is it from "unusual life" to "life" so unusual we don't consider it life at all?