----- Original Message ----- From: LARRY KLAES To: europa Sent: Wednesday, October 30, 2002 7:16 AM Subject: Could Mars life have landed on Europa as well? ___________________________
There's a very interesting and important scientific issue connected with this. The idea that meteorite exchanges may have transferred ancient microbial life from Earth to Mars -- or, more likely, Mars to Earth, given Mars' lower gravity which makes it far easier for giant impacts to blast chunks of its surface rock to escape velocity -- is really starting to catch on among scientists. But it means that, even if we find evidence of life on Mars, unless it's really radically different biochemically there's a good chance that we'll never be able to tell whether or not it actually evolved separately on Mars or is simply an ancient Earth transplant! And, more generally, finding such life on Mars would not do anything to prove that life is common in the Universe -- it could easily have originated as an extremely rare chance biochemical event on either Earth or Mars and then simply spread to the other planet. But Europa is much farther away (and any meteorites from the inner Solar System crash into it at tremendously higher speed, given Jupiter's powerful gravity) -- so if we find Europan life, the odds will much higher that it is indeed native to Europa. And so Europan life would be much stronger evidence than Martian life that life is indeed a common phenomenon in the Universe, appearing on most of the worlds where conditions allow it at all. == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
