Mars-water discovery intrigues UA scientist

Pond could give rise to life, he says

FAYETTEVILLE — A water pond spotted beneath the surface of Mars marks a turning point in the search for life on the red planet, scientists say.

“It could be really significant and alter the way we are trying to find life on Mars,” said Vincent Chevrier, a University of Arkansas, Fayetteville assistant research professor at the school’s Arkansas Center for Space and Planetary Sciences.

Chevrier, not a part of the study that announced the findings Monday, said liquid water had previously been discovered on Mars on a “very small scale” and not always at the same locations.

Italian researchers said evidence gathered from the radar signals of an orbiting spacecraft suggests a 12-milewide reservoir buried near the planet’s south pole, The Associated Press reported.

Information was gathered by what’s known as the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument, which was deployed on the European Space Agency’s Mars Express spacecraft, according to the agency.

“This subsurface anomaly on Mars has radar properties matching water or water-rich sediments,” Roberto Orosei, the principal investigator,

said in a statement released by the agency. Orosei is with Italy’s National Institute of Astrophysics, The Associated Press reported.

Detection via radar signals means that the thickness “would need to be at least several tens of centimeters thick,” according to a statement by the European Space Agency, which described the body of liquid water as “possibly laden with salty, saturated sediments.”

“This could be, perhaps, the first habitat we find on Mars,” said Orosei, who led the study published in the journal Science, according to The Washington Post.

Chevrier’s work, funded by NASA, has involved studying the effects of salt on the stability of liquid water under conditions like those on Mars. He said the announcement might mean scientists pay more attention to what lies below the surface of the cold planet.

“If life ever arose on Mars, I would say that what has been discovered today, that subsurface lake, is probably one of the best spots where we could find life,” Chevrier said.

Scientists elsewhere tried to assess what the finding might mean about the possibility of life on Mars.

“This water would be extremely cold, right at the point where it’s about to freeze. And it would be salty. Those are not ideal conditions for life to form,” Kirsten Siebach, a planetary geologist at Rice University who wasn’t part of the study, told The Washington Post, though she added that microbes on Earth have been able to adapt to similar environments.

Chevrier and other UA scientists have studied the possibility of life on Mars.

Rebecca Mickol, a former UA graduate student, and Tim Kral, a UA biological sciences professor, wrote about the possibility of certain types of microorganisms surviving and growing on Mars in studies

published this year by the academic journal Planetary and Space Science.

They focused on what are known as methanogens, which are common on Earth, doing research in UA simulation chambers. The chambers allow for experiments in pressure and temperature environments similar to conditions found on other planets.

“If there is actually a substantial liquid water reservoir or aquifer of some sort, I think that definitely increases the chances of life on Mars — bacterial or microbial life,” said Mickol, now a postdoctoral fellow doing research at the Naval Research Laboratory in Washington, D.C.

However, Kral, in an email, described the Monday announcement as saying “nothing new” about the possibility of life on Mars.

“We are fairly certain that there is liquid water below the surface. This would confirm that IF it is true,” Kral said.

Chevrier spoke about next steps for research. He said he’d like to see additional measurements by the same radar instrument showing the same finding. Chevrier also said that, to help with confirmation, he’d like to see if NASA technology known as the Shallow Radar sounder can also find the same evidence.

If the confirmation holds up, “we don’t know why it’s there,” Chevrier said, noting the low temperatures of Mars. “What helped the liquid water to be stable?”

A water pond would suggest the presence of salts that, like on icy roads, lower the freezing point of water, he said. Or, perhaps there is a nearby heat source, he added.

Chevrier said he also wanted to know how old the body of water might be. Conditions most favorable to life generally involve having liquid water available for long periods of time, he said.

Questions remains, but he called the Monday announcement “a boost for the hypothesis that there’s still a possibility of Mars harboring life today.”