NASA has announced the discovery of a life form - a microbe - that incorporates arsenic into its biochemistry. This is important because it opens the possibility of life forms that don't depend on the same sorts of elements that we depend on. We have evidence of such life forms right here on earth, so there's no reason at all to think that "hostile planetary surfaces" are necessarily "hostile" if you're built to live there.
Turning a probability vector into a state
3 hours ago