>I side with atmospheric chemist James Lovelock on this. Mars has a
>chemical steady-state atmosphere, (and very little of that) and
>therefore it is unlikely that it supports life.
There are good arguments either way. I predict that we will find extant microbial life, but that's just me. What's truly fascinating, ironically enough, is the potential of finding a _dead_ biosphere. Mars wasn't always steady-state...