> I've seen some tantalizing photographic evidence that might.... > just might show fossil evidence, of low life forms that had > lived in the water and mud when Mars was still a wet planet.
My slight understanding is that Mars does not have a high enough gravity to retain enough air for a very significant air pressure. And that the air pressure it has, or could ever have had, is not enough to keep liquid water from evaporating into space. Unless the rate of evaporation was slow enough so that there were large bodies of water for millions of years, how could there have been life in the water and mud, or at least life complicated enough to have left fossils?
