[Question_Assumptions]

I should also add that there are parallels in the search for life on Mars. The idea is to look at rocks and the chemistry of Mars and determine whether there is any evidence of water or life that existed in the past but no longer exists and can no longer be observed. Is that not science because they can't observe life on Mars happening, can't model it mathematically, and can't plug it into a computer model to get a definitive result? Or will they just look at the evidence and assess the probability that various things happened naturally ore were produced by water and/or life?

[js1138]

There is no foolproof test for alien life. We have been examining martian chemistry for twenty years or so and still don't know exactly what to look for.