Large freshwater lake on Mars could have been hospitable to life

Dec. 9 (UPI) -- A string of studies published Monday suggest that an ancient freshwater lake existed on Mars and could have been hospitable to life.

The studies published in the journal Science suggest that the lake, thought to have existed 3.5 billions years ago, lay in the Gale Crater floor, the same crater where the Mars Curiosity rover landed in 2012.

The lake may have existed for hundreds or thousands of years and its timeline is almost similar to when life started on Earth.

“You can actually begin to line up in time what the Earth was doing and what Mars was doing,” Dr. John Grotzinger, a professor of geology at the California Institute of Technology, told The New York Times. “It’s kind of cool.”

According to Grotzinger, microbes, similar to some present on Earth, could have inhabited the lake and thrived in its environment. These microbes would have been similar to chemolithoautotrophs, which are found on Earth and live in caves, hydrothermal vents and deep underground.

The findings are derived from the analysis of two mudstones, called John Klein and Cumberland, drilled by Curiosity earlier this year. The clays appear to have been formed at the bottom of the lake and not swept down from the walls of the crater, suggesting the lake wasn't acidic. The structure and chemical makeup of the rocks were very similar, almost Earth-like.

In 2004, NASA's Opportunity rover found that various Martian locations were at one time soaking wet, and these were initially thought to have been suitable for life. But on detailed analysis researchers found that these locations were too salty and acidic.

The surface of Mars today is arid, cold and constantly bombarded by radiation, not at all suitable for life. But these findings suggest that at some point Mars could have been hospitable to life, and also closely matched the beginning of life on Earth.

[Science] [The New York Times]