Art
> Maybe they ought to ask how they can ever expect to find evidence for life
> on Mars (the presumed impetus behind the probes) when they can't concoct a
> reasonable scenario for having it happen here.
Chris
I think part of the idea is that, if life ever did exist on Mars, the
evidence of how it originated may not have been buried by the detritus of
later life. If life once existed and then died out after a short while, it
would make *much* more manageable evidence. Further, if life once existed on
Mars, and it is found but found to have been radically *different* from
Earth-life (based on a different basic set of molecules and a different
genetic mechanism, that would be extremely valuable as well).
Art
> Certainly nobody would
> assert that the Martian environment was more hospitable to life than the
> one posited for earth!???
Chris
It's not more hospitable *now*, but it may have been at one time (with a
much thicker atmosphere, for example).
Art
> Of course all of us want to learn more about the
> planets and the universe, but it isn't much fun to see billions of dollars
> being lost in an effort directed toward an unrealistic goal.
Chris
I'm not sure it's unrealistic, but I agree that it isn't much fun. I would
even argue that it's not the sort of thing tax dollars should be used on at
all, as much as I personally would like to see such things done.