Posted: Tue Oct 17, 2006 10:36 am
Well I recall reading on some paper that the main reason why life is carbon based was that it was the most common complex chemistry of all the possibles (there're around 20 chemical elements that can act as basis of complex chemistries, other candidates wer Si, N, etc..) and on earth there were the among the most ideal conditions for that chemistry to develop, though it's possible that on other environments there could be other possible chemistries (like N or NH3 based life for gas giants, or Si for mercury alike planets).
The main reason to look for life in mars is that it has had an evolution very similr to earth and there might be the possibility that the same process that lead to the appeareance of life in earth happened in mars, since it had a thicker atmosphere and probably liquid water for a period of time. Also there's the reason that original tests made by viking-1/2 spaceships were inconclusive regarding life on mars, and there're reasons to belive that there might be still some kind of biological activity that replenishes the methane found on mars atmosphere -though it could be of non organic synthesis, it's one of the signs that usually confirms biological or organical activity-
The main reason to look for life in mars is that it has had an evolution very similr to earth and there might be the possibility that the same process that lead to the appeareance of life in earth happened in mars, since it had a thicker atmosphere and probably liquid water for a period of time. Also there's the reason that original tests made by viking-1/2 spaceships were inconclusive regarding life on mars, and there're reasons to belive that there might be still some kind of biological activity that replenishes the methane found on mars atmosphere -though it could be of non organic synthesis, it's one of the signs that usually confirms biological or organical activity-