[meteorite-list] Mars life concerns

From: Matson, Robert <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Mon Jul 18 16:31:02 2005
Message-ID: <BE076B8CCE4CFE4D9598230D888B2ADF07C838_at_0005-its-exs01.mail.saic.com>

Hi Darren,

> Personally, I think that the "not mess around" part only really applies
> to worlds that have life (like Earth, for instance). Any dead rocks
> (like probably everything else in the solar system) I think are fair
> game.

But I think the point here is that we don't KNOW that Mars is a dead
planet. Given the tenacity of microbes and the possibility that life
on earth itself may have been initially delivered by comets or meteoroids,
is the possibility of (primitive) life on Mars all that hard to fathom?
The planet has water and internal heat sources to allow it to exist in
liquid form under the surface. I think the Vegas odds of life on Mars
are not all that long.

Once you accept that Mars life is possible (and I personally might go
so far as to say ~probable~), then there are scientific and perhaps even
ethical considerations as far as potentially contaminating that life
with spacecraft hitchhikers from earth. For example, suppose many years
from now that a lander experiment unambiguously discovers life on Mars.
Without sophisticated tests, you probably won't be able to differentiate
between Martian indigenous life and earth life (unintentionally trans-
planted by one of the many Mars landers of decades past) that has
managed to gain a foothold somehow. (This problem goes away if
you're talking about a sample return mission.)

--Rob
Received on Mon 18 Jul 2005 04:30:38 PM PDT