Seriously, in “Is there life in them thar Martian pits?” (MSNBC.com, 4/5/2012), Jason Major reports,
Like similar features found on Earth, lava tubes on Mars are the result of rivers of magma that carved channels beneath the surface. When these channels empty out, a hollow tube is left. If the roof of a particularly large tube is near the surface, the roof can eventually collapse, creating a surface depression — or in some cases, opening up to the surface entirely.
Even though volcanism on Mars isn’t currently active — the last eruptions probably took place at least a million years ago — the features left by volcanic activity are still very much present today and probably well-preserved beneath the Martian surface.
Shielded from harsh solar and cosmic radiation, the interior of such lava tubes could provide a safe haven for microbial life — especially if groundwater had found its way inside at some point.
Of course, the principle difficulty isn’t how life might have survived there, but how it came to exist there.
A shame because space exploration is a non-military use of science – competitive but not violent, with a chance of learning something useful. Put another way, if we save the money from exploration, will we then spend it on wars, learning nothing? Also, absent exploration, mere “there’s just gotta be life!” speculation gains more force than it will otherwise have.
See also: In the days when Mars had life, the 1970s …
Current search for life on Mars features dramatically reduced expectations