alt Hacker NewsThere are questions about methane in the Martian atmosphere. Again, there is some ambiguity as to why.
However, we have found life in some very hostile environments on Earth, notably high up in the atmosphere. Planococcus halocryophilus can exist on Earth at -20' C, well within Martian surface temperature ranges, and is tolerant of very salty water. Microbes need a fraction of the resources we do, and some can exist in very small numbers for long periods before better conditions come along. Surface temperatures on Mars have been observed to go over 20' C during the day in some places which may allow for some warmth to penetrate rock and dust. A very hostile environment, to be sure.