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Space theorist posits unusual life on Mars: San Francisco Chronicle

  1. Sep 5, 2003 #1

    Ivan Seeking

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  2. jcsd
  3. Sep 8, 2003 #2
    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).
  4. Sep 8, 2003 #3


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