Re: life test for planets

From: Mike Lorrey (
Date: Sun Jan 27 2002 - 12:46:24 MST wrote:
> I'm sure that what you have described is what all interested parties are most
> concerned with, the identifiable of biotic planets. So if the biology is
> chlorophyl, or rhodopsin, this is less important then that such life exists.

Yes, however being that chlorophyll is more efficient than rhodopsin at
photosynthesis at atmospheric densities and gas concentrations similar
to that of our current climate, and that human civilization is the only
currently known example of intelligent technological life forms, logic
demands, if we are searching for other similar species, to focus on
discovering other worlds with similar spectral features. Furthermore,
such worlds are of immensely greater importance to humans if we ever
master interstellar travel than any other planetary body.

> One other opinion. The notion that many educated people seem blase' about
> life previously existing on Mars (for example) to me seems wrong-headed. If
> life was ever demonstrated to have lived on Mars, it would surely alter
> humankind's' perspective on the universe.

However, this is immaterial to the present discussion about our ability
to sense current life on earthlike extrasolar planets through spectral
analysis. Few intelligent people today doubt that such life exists, and
many are aware that Mars once had a climate very similar to that present
on Earth today which would have been conducive to the formation of life.
The fact we can't currently sense such a photosynthetic signature on
Mars is indicative of it's current sterility, at least on the surface.

This archive was generated by hypermail 2.1.5 : Fri Nov 01 2002 - 13:37:36 MST