QUESTION: 
Would it be possible that life still exists deep under Mars ?  An article
in the October issue of Scientific American discusses microbes that live
deep underground on Earth, as far as 2.4 kilometers below the surface
where temperatures reach 75 deg C.  If life can thrive under such harsh
conditions would it be possible that life still exists deep under Mars ? 

ANSWER from Cheick Diarra on November 19, 1996:
It is possible that life exists in the Martian underground. Actually that 
is probably the only place where life, as we know it, might survive on Mars. 
The Martian atmosphere is so thin that the radiation from the Sun has 
sterilized the surface. I think that if we are to find life today on Mars, 
it will be underground (my opinion). Future missions will have penetrators 
which could tell us more about the conditions down there.