[meteorite-list] Quarter of Mars Scientists at European MeetingBelieve Life Possible on Mars

From: Francis Graham <francisgraham_at_meteoritecentral.com>
Date: Mon Mar 21 13:24:53 2005
Message-ID: <20050301221918.26503.qmail_at_web54705.mail.yahoo.com>

--- Marc Fries <m.fries_at_gl.ciw.edu> wrote:

> Howdy
>

  A friendly hello to all concerned with this
perplexing issue,

> Keep me off that list, even if the NASA
> Astrobiology Institute is
> paying my bills nowadays. Methane can be produced
> by geology,
> formaldehyde is a natural by-product of methane in
> Mars' viciously
> oxidizing environment, and hexaoctahedral magnetite
> can be produced
> abiotically.


   All correct, I can't argue. But the argument runs
that these events are more-or-less independent
abiotically (except for the formaldehyde-methane link)
, and not so if biology is involved, so the biological
origin is increasingly more probable. Keep in mind
that was McKay et al's argument in ALH 84001: these
things are all in the same rock, and their association
would be improbable if they were abiotic, although
each might be produced somehow abiotically. The
counter to that was: well, we have only one rock as an
example.
  My remarks meant to look to the future of this
issue.
  More news came out in today's Aviation Week. It
turns out, according to the article, that Elysium
seems to be an ice lake the size of the North Sea on
Mars, covered by volcanic ash. (Elysium is visible as
an albedo feature from Earth ) And they report the
methane is enhanced over it, exactly as it should be
if biology in the underlying ground water were a
factor, but only coincidentally if geology were.

> This is
> a serious question with a thousand important
> implications, and We can't
> accept a partial answer or rushed judgement to it
> either way.

   I could not agree more that a healthy scientific
skepticism is in order here. But, as future evidence
comes in, should we cling to nonbiological
interpretations with desparation? What is the criteria
for saying, "Gee. It sure looks like Mars has or had
some sort of biology." ? If it is required that all
possible nonbiological ad-hoc explanations be
comprehensively disproven then it may take some time
to get there. Is that what you are saying?
   It would be OK to say that, IF the implications of
even a tentative conclusion about life on Mars (and
all science is tentative) were so abhorrent that we
must not embrace it unless forced to. Are the
implications of saying microbiotic life is probable on
Mars so abhorrent that we must not think it unless
forced to? And why?
  You may well be correct that we may not be to the
point yet of saying life exists or existed on Mars.
But: the news comes in as you say, daily (and faster
than the journals can print it) so at what level do we
say so? What are the lines to be crossed? And: can we
not now today speak of at least probabilities? You
must admit, the probabilities look better and better,
and as the probability of biology increases, things
begin to fit together, and the probability of a
lifeless contrary Mars decreases.
  True, I am a little troubled by some things on a
biological Mars model that don't quite fit, but they
can be explained by a biology on Mars that is barely
hanging on, as did Earth's biology during some of the
equator-to-pole freezes of our own Archaean and
Proterozoic times. Except on Mars it has been so for
billions of years.
  Of course, if Mars had anything like a visible
biosphere above the surface this issue would not even
be here. We are really indirectly looking into dark
water-filled crevices below the cryosphere with
sniffing instruments. We can indeed reach tentative
conclusions in science by indirect evidence. If Mars'
deep life is chemosynthetic in crevices underground,
the kind of absolute solid direct proof many desire
may not be forthcoming ever at all, and the indirect
evidence may be it.
  I can hardly wait to see the next Division of
Planetary Science meeting papers.

Francis Graham





                
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Received on Tue 01 Mar 2005 05:19:18 PM PST