Caves on Mars

Boston sees caves as more than just another extreme environment.

"We have thought about what the life might look like on the surface [of other worlds], but in light of the huge biodiversity of microorganisms in the subsurface of Earth, the subsurface in general and caves in particular will be an important place to look for life on other bodies," Boston said. "I believe that there may be many planets, including Mars, where the only life on the planet will be restricted to the subsurface."

As the team finds out more about how cave microbes thrive in the extreme environment of earthly caves, they’ll learn more about what chemical and crystalline signs to look for in what may be the normal environment of other planets.

What’s next?

The team plans to continue exploring known caves and to search for caves with unique environments. Each environmental extremity offers new challenges to microbes living there and therefore new challenges in growing those microbes in the lab. But the effort may pay off in new clues to look for in the search for life on other planets.

Cave microbe research wouldn’t be complete without a space mission, and Boston has one in the works.

"The experiment was originally scheduled for the Space Shuttle this summer," she says.

With the shuttle fleet grounded, Boston’s experiment will instead ride to the Space Station aboard an unmanned Russian Progress vehicle. Boston will grow a bacterial strain that produces unique mineral crystals in the microgravity of near-earth orbit.

"Because microgravity is known to affect the growth of crystals," she says, "we hope to gain insight into the fundamental crystal-producing mechanisms of our organisms."

"In the meantime, Boston says, "we are plowing through laboratory analyses of samples from previous trips. For every hour in the field, you can figure on about 100 hours of lab followup or more, so we are always behind!"