Mars cave-exploration mission entices scientists

NASA is mapping out a strategy to return bits of rock and soil from the Martian surface to Earth, but the most intriguing Red Planet samples lie in underground caverns, some scientists say, Space.com reports.

The space agency's next steps at Mars are geared toward mounting a sample-return mission, which is widely viewed as the best way to look for signs of Red Planet life. Such signs are perhaps more likely to be found in material pulled from the subsurface, so some researchers hope NASA's first Martian sample-return effort won't be its last.

"While I'm very much interested in a surface sample-return to get us over this hump of doing it, of course I immediately want to go on and start sampling more cryptic materials in lava-tube caves," said astrobiologist and cave scientist Penny Boston, of the New Mexico Institute of Mining and Technology in Socorro.

Subterranean formations are quite common on Mars, Boston said. Orbiting spacecraft have spotted many snaking lava tubes, for example, which were created by long-ago Red Planet volcanism.

"Something like the lava tubes could be wonderful traps for material from past climate regimes, particles from previous epochs on Mars," Boston said, noting that liquid water is known to have flowed across the Martian surface long ago.