Panspermia in the news (again)

[Ken Kinman]

Dear All,
      Ever since that Martian meteorite was found back in the 1990's (with possible microbial fossils), some at NASA have really pushed this idea of panspermia----life on one planet seeding life on other planets (or moons).  Okay, I can see how a meteorite could occasionally carry small fossils between planets, but for a living microbe or spore to hitch a ride, survive hundreds of thousands (much less millions) of years of cosmic irradation, and reentry onto a foreign world----well, I just don't buy it!!!

     Yes, I know there are bacteria and spores that are extremely radiation-resistant, but do they have a shelf-life of hundreds of thousands of years (even if they managed to survive all the other obstacles such a scenario entails)?  Seems to me the probability is much higher that any planet or moon with an environment conducive to life would develop its own life independently long before some "seed" managed to get there from outer space.  Anyway, here's a link to the latest panspermia story:

http://news.bbc.co.uk/2/hi/science/nature/4819370.stm

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