Could the planet mars support life?
If may have been able to support life long ago when it had a much denser atmosphere but that life wouldn´t have had much time to become advanced beyond single celled had it evolved at all. It took 3 billion years for life to even get multicellular on earth. On Mars life would have gone extinct as the atmosphere vented off into space unless some of it found a subterranean cave refuge beneath the surface where heat from some faint geological hotspot has kept liquid water while keeping the cave protected from the harsh martian surface environments. We have found traces of massive cavesystems near the big volcanoes which just happen to be hot spot volcanoes. http://antwrp.gsfc.nasa.gov/apod/ap07092… Of course when a cave collapses like this any life within would be doomed…
If there are remaining hot spots in the Martian crust it is possible that some form of extremeophile martian life still exists. But since its core appears to be solid, the chances of this are low. If you mean human life then only in very expensive habitats that would be rather pointless to build. Such constructions and the machinery to operate them require a source of spare parts. If something goes wrong you do not have the luxury of ordering parts from earth. You would die waiting. Perhaps with extremely advanced nanotechnology and robotics living on mars would become survivable. But with anything we can do today, you had better have a death wish to even visit Mars.
