[meteorite-list] Alien Microbes Could Survive Crash-Landing

From: Marc D. Fries <m.fries_at_meteoritecentral.com>
Date: Sat Sep 18 18:34:58 2004
Message-ID: <1195.69.140.192.34.1095546894.squirrel_at_webmail.ciw.edu>

ALH 84001 definately carries biomarkers. The meteorite supports a range
of terrestrial contaminant microbes from its time spent in Antarctica.
May I suggest:

"Investigations into an unknown organism on the martian meteorite ALH
84001", A. Steele et al, MAPS 35, 237-241.

and

"Isotopic evidence for a terrestrial source of organic compounds found in
martian meteorites ALH 84001 and Elephant moraine 76001", A.J.T. Jull et
al, Science 279, 16 Jan 1998.

ALH 84001 will never serve as conclusive proof of life on Mars one way or
the other due to terrestrial contamination. That's one that we can go
'round and 'round over but won't have a real chance of understanding until
we actually go to Mars. That may be Mars' best "use" to us - testing our
ideas of what is necessary for life to arise on a given planet.

Cheers,
MDF

> Dear List,
> Back in 1999 it seemed to me that in order for there
> to be no life having ever existed on Mars one of two
> conjectures, or both, must be true.
> 1. It is absolutely impossible for viable spores to
> be transported by any natural process from the Earth
> to Mars (No Free Ride Conjecture).
> 2. There was never any environment on Mars that
> could have supported a positive growth rate for such
> organisms if they did get there. (Killer Mars
> Conjecture)
> Since 1999, recently, the Mars rovers have shown
> that the Killer Mars Conjecture is false. And the work
> of Burchell et al as described is evidence that the
> first conjecture is false also.
> Even if Burchell's mechanism is improbable, that
> won't do, as there have been billions of times matter
> has been exchanged between the planets due to impacts.
> There are plenty of chances in 4 billion years. The
> odds need to be vanishingly small.
> I'm leaning toward the minority who think that ALH
> 84001 has biomarkers. Although most of the biosignal
> in ALH 84001 can be produced abiologically, it can
> also be produced biologically, and in light of the two
> conjectures above being false that interpretation
> seems more reasonable.
> Comments?
>
> Francis Graham
>

---
Marc D. Fries, Ph.D.
Postdoctoral Research Associate
Carnegie Institution of Washington
Geophysical Laboratory
5251 Broad Branch Rd. NW
Washington, DC 20015
PH:  202 478 7970
FAX: 202 478 8901

Received on Sat 18 Sep 2004 06:34:54 PM PDT