they said on tha space program the other night that Bacteria or other lifeforms could live beneath mars surface.
Theres some on our planet that breath carbon dioxide an release Acid
theres even bacteria that live in solid ice O_O
Don't forget the ones that survive in the extreme heat and pressure by volcanic vents in the deepest parts of the ocean. I think there's enough evidence on our own planet to suggest that life most likely exists on other worlds. Then theres the Drake Equation too.