In a message dated 12/11/99 22:27:59, firstname.lastname@example.org wrote:
>Sounds kind of cool, to think that some living material has been going
>back and forth, on occasion, all along! Do you have any more detail on
>this, was the last possibly "viable" transfer apt to have been a million
>years ago, or ten million years ago, or something?
Yes, it is very cool. Life crossing interplanetary space, wow. I understand it's an occaisional thing but I don't have details. We don't have detailed information even on the occurances of major asteroid strikes on Earth, just rough frequency analyses.
>If we get in a hurry
>to transfer some significant living material to Mars, *now*, doesn't
>that run the risk of confusing the whole issue, so that you'd wish you
>could've at least ruled out the chance that what's under your microscope
>was maybe brought along by astronauts, just lately?
Very much so. However, I think most scientists are more interested in Mars science in general than in the possible history of Earth- biotransfers. If, as we currently think, the surface of Mars is currently sterile then our introductions won't cause any trouble anyway.
>To risk sending humans very soon still sounds to me
>sort of like sending whole "boatloads" of potential bio-contaminants,
>possibly to the point of confusing some important life search results.
Quite true. Most things can't survive a year-long trip in outer space. Many more organisms could transfer along with people. If Mars is sterile, it will make no difference; even if Martian life exists but is confined to the deep subsurface contamination is a remote possibility. To most scientists, the risk-reward of Martian exploration is still positive.