At 11:25 AM 12/19/2014, Warren D Smith wrote:
Looking glum for life on Mars.
--actually, here's what seems to me a pretty convincing argument there is not life on Mars!
From Wikipedia "Perchlorate":
I'm more interested in previous life on Mars. The early Solar system was a pretty chaotic place, and it would appear that some oxygen-generating life forms got started on Earth within the first 1-1.5 billion years. Do to the celestial chaos, there were likely a large number of significant meteor impact events as big or bigger than the one on Earth 65 million years ago. So IMHO it is highly likely that we will eventually find traces (likely dead) of early Earth organisms on Mars. The next question is whether early Mars could sustain life or not; I think that that question is still unanswered. But even if early Mars could sustain life, I would think that if Mars is dead now, then it was probably dead 65 million years ago, as well, so we might also still find traces of 65 million-year-old Earth life on Mars. If Mars developed life prior to Earth, then unless Mars life was transported to Earth and became Earth life, then Mars life could be substantially different from Earth life -- e.g., perhaps mirror-imaged proteins (50% probability), etc.