[meteorite-list] Mars life concerns

From: Marc Fries <m.fries_at_meteoritecentral.com>
Date: Mon Jul 18 23:17:06 2005
Message-ID: <1750.69.251.197.11.1121743019.squirrel_at_webmail.ciw.edu>

Howdy all

   I noticed the microbes-on-spacecraft thread earlier today but put off
an answer until "later". Now I see that the list is all a-froth - wow!
   First off, the microbes on the Surveyor camera were most likely
introduced by the astronauts themselves during handling. The camera
was kept in the Apollo lander and then the command module along with
the astronauts, without any sort of contamination protection, for the
entire trip back to Earth. Between them and the NASA ground staff that
unloaded the Apollo module and what-not, by far the easier answer for
the presence of common human-dwelling microbes is introduction by
contamination rather than extended survival in a radiation-heavy hard
vacuum.
   Secondly, panspermia is bunk. Search out my earlier posts on that
topic if you're interested.
   Third, all microbes placed in Mars simulation chambers eventually die.
Some will survive if you return them to Terran conditions relatively
quickly, but all will eventually perish or become nonviable spores
(same thing, really).
   And finally - the original question - NASA does sterilize spacecraft
before they are launched. Modern craft have to pass sterilization
protocols before launch, and they are so stringent that we will have to
figure out a way "around" them in order to send any of the next
generation of high-sensitivity, antibody-based life detection
instruments out and about. (Current sterilization protocols would
destroy the antibodies) Now, as stringent as NASA requirements are,
there are two problems. For one, earlier craft have already been sent
under far less stringent requirements (including crashed orbiters), and
two - no sterilization routine is perfect. However - and here's where
reality kicks in - you're sending these spacecraft to a place that is
similar to the inside of a scanning electron microscope. Better yet,
an SEM in Antarctica. Anything that survives on Earth will be
irradiated, freeze-dried, and will find out just how hard it sucks to
try to live in a vacuum (ha ha). Even if they bend the laws of physics
long enough to sporulate, they're still hosed eventually. So the short
version is yes - we've most likely lofted microbes to Mars. They're
some seriously dead-ass microbes today, however.

Cheers,
MDF

> Rob M. wrote:
>
>>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?
>
> Thanks for keeping things in perspective, Rob. Goran, I just saw your
> post
> too. Rest assured, there is nothing we can do about Europe at this
> point,
> and maybe after reading this post, you will re-evaluate all of your
> reasons why
> microbes can't survive. The fact is that they can and have survived
> worse
> conditions on primitive spacecraft (less protection):
>
> Don't forget the Apollo mission that recovered the camera from the austere
> Surveyor 3 lander,
> after a tough trip and more than 2.5 year vacation on the Moon, in vacuum,
> without any food or water, surviving the conditions of transit and all the
> radiation thrown at them. Perhaps they didn't reproduce, but the
> _Streptococcus
> mitas_ bacteria were sure virulent when they were cultured back on earth
> by
> the US Center for Disease Control.
>
> In Apollo 12 Commander Pete Conrad's words:
> "I always thought the most significant thing that we ever found on the
> whole...Moon was that little bacteria who came back and lived and nobody
> ever said
> [anything] about it."
>
> It is sad to say that whether there is life on both Mars and the Moon is
> probably a moot question by now. The questions are, how bad the infection
> IS,
> and whether there WAS life on either of those worlds...
>
> For more information see:
> _http://science.nasa.gov/newhome/headlines/ast01sep98_1.htm_
> (http://science.nasa.gov/newhome/headlines/ast01sep98_1.htm)
>
> It really isn't in NASA's interest to publicize this too much, of course,
> or
> some burocrats could always misuse or heavens, ask for higher standards of
> protection. Panspermia in action!
>
> Saludos, Doug
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-- 
Marc Fries
Postdoctoral Research Associate
Carnegie Institution of Washington
Geophysical Laboratory
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Received on Mon 18 Jul 2005 11:16:59 PM PDT