From: knapp@spot.Colorado.EDU (David Knapp)
Subject: Re: Seeding Mars with life
Organization: University of Colorado, Boulder
Date: Fri, 14 Aug 1992 02:06:32 GMT

In article <20652@sbsvax.cs.uni-sb.de> dietz@mpii01036.NoSubdomain.NoDomain (Paul Dietz) writes:
>In article <1992Aug11.153858.24328@ucsu.Colorado.EDU>, knapp@spot.Colorado.EDU (David Knapp) writes:
>
>|> >|> You don't know that, and, in fact, nobody else does either. There is
>|> >|> strong evidence that there exists abundant water supplies within the 
>|> >|> Martian regolith.
>|> >
>|> >There exists abundant water of hydration, and ice, probably.  But *not*
>|> >liquid water anywhere near the surface.  The pressure is simply too low.
>|> 
>|> I contend that the subsurface of Mars is as much on Mars as the surface is
>|> and that if water exists there in liquid form, then liquid water exists on 
>|> Mars, which you said was impossible.
>
>Oh, good grief.  I said "on Mars".  Not "in Mars".

Which, as far as life is concerned, doesn't make a lot of difference.

>|> >Life exists at depth on earth only because it also exists at the surface.
>|> 
>|> I think you've suggested a cause an effect that most biologists would
>|> disagree with.
>
>Name one?

I will ask if I can use his name.

>
>|> >Soil organisms decompose organic compounds produced by photosynthesis.
>|> 
>|> Photosynthesis isn't required for all life. Not all life forms consume 
>|> products of photosynthesis. Deep ocean vent tube worms are one example.
>|> 
>|> >Deep organisms that eat oil run on fossil photosynthetic energy.
>|> >Even the "vent" organisms are exploiting the chemical gradient set up
>|> >by photosynthesis (they oxidize the reduced chemicals coming out of the
>|> >vents), and are therefore not completely geothermally powered.
>|> 
>|> The do not comsume photosythesized materials. (at least according to National
>|> Geographic...)
>
>
>Perhaps you had better get your biological information from
>a different source, then.  Oxygen is a photosynthesized material,
>you know.

This doesn't mean there cannot be life using other means of respiration. And
even if all possible lifeforms in the universe just happened to respirate
oxygen (which I wouldn't assume) there may be resorvoirs of oxygen large 
enough to supply a small population of organisms with respiratory material.
Or, there may be other reducing mechanisms *within* the lifeform.

You forget we're talking about life on Mars, not life on Earth. Life on Mars
is about as absurd as putting a man on the moon. The only reason we might
think it's a silly thought is because we haven't seen it yet.

> If all photosynthesizing organisms on Earth were
>to be killed, the tube worms would die out when the
>atmosphere's oxygen was depleted (which would take a few million years)
>or when the oceans became anoxic.

And why do we need photosynthetic material to produce the free oxygen? Only
because there are mechanisms on Earth which would otherwise take up all the
oxygen and we'd be left with a lot of oxidized materials. That is correct,
as far as we know, *here*. Not everywhere. And we haven't even found or
classified all life *here* yet.

Do you know of all the oxygen processes occurring everywhere on Mars? This is
the point. You are arguing from a lack of knowledge of the Martian surface,
subsurface, atmosphere etc. In fact, we all do. We know very little about
Mars when it comes down to it. Which is why I assert we should take all
precautions to influence it as little as possible.


-- 
David Knapp                                      University of Colorado, Boulder
Highly Opinionated, Aging  and                      knapp@spot.colorado.edu
Perpetual Student of Chemistry and Physics.
            Write me for an argument on your favorite subject.
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