Martian Volcano Could Be Reservoir for Life

Scientists searching for life on Mars should start digging under Olympus Mons.

New research shows that liquid water probably once sloshed beneath the 15-mile-high volcano. It may still be there, and it may be nice and warm, thanks to volcanic heat.

"Olympus Mons is a favored place to find ongoing life on Mars," said the study's lead author, geophysicist Patrick McGovern of Houston's Lunar and Planetary Institute, a branch of the Universities Space Research Association. "An environment that's warm and wet, and protected from adverse surface conditions, is a great place to start looking."

McGovern and co-author Julia Morgan of Rice University modeled the formation of Olympus Mons using computer simulations. They determined that the volcano's strange asymmetry — it has a gently sloped northwest flank and a much steeper southeast side — is the result of what lies beneath it. Lava probably spread so oddly because it slid on something slippery, they argue in a new study, which appeared in the February issue of Geology.

"In order for the volcano to have that unusual shape, you need some sort of low-friction base," McGovern said.

Clay, which is deposited by water, is the most likely foundational material. The same phenomenon is seen in some Hawaiian volcanoes, according to McGovern. And we already know there is clay on Mars: the European Space Agency's Mars Express spacecraft has already detected it.

Olympus Mons is about 340 miles wide, so clay beneath it "would correspond to a huge amount of water," said geochemist Jennifer Blank of the SETI Institute in Mountain View, California, who was not involved in the study.Better yet, unlike the long-suspected water ice that the Phoenix lander sampled for the first time, if water does exist under Olympus Mons, it might well be piping hot. The lack of of impact craters on the volcano's surface indicates that it was active until no more than 10-20 million years ago.

"On our time scale, that's pretty close to current," McGovern said.

Despite what seems like a lack of recent eruptions, the volcano could still be warm on the inside, although the researchers admit that's still speculative.

If the environment beneath Olympus Mons is hot, wet, and dark, it would mirror the conditions that many scientists believe gave rise to life on Earth.

"Some of the most primitive life forms on Earth are thermophiles," Blank said. "And they're underground. They don't need light."

Other discoveries also hint that life may exist–or may once have existed–on Mars. Over the years, scientists have found equivocal evidence of life in Martian meteorites and on the Martian surface. And in January, researchers documented methane burps on the Red Planet, which could indicate microbial activity. But so far, it's all about "if" and "could be."