Quite a few articles (
CNN story here)on new images taken of Mars that scientists think could indicate water having flowed recently on the surface of the Red Planet. This further raises the possibility that life exists on our closest neighbor.
I may be going out on a limb, but I think the "water" is the first sign of a Martian sewer system. They obviously have to live underground, so where do you think they would pump their toilet plumbing to when they flush???? Call me crazy... crazy like a fox.