This evenly layered rock photographed by the Mast Camera on NASA's Curiosity Mars Rover in August 2014, shows a pattern typical of a lake-floor sedimentary deposit not far from where flowing water entered a lake. (NASA)

Water on Mars may have been more prevalent than originally thought, according to new data from NASA’s Curiosity. The rover recently observed that Mount Sharp in Gale Crater — the three-mile high peak NASA’s been studying — was “built by sediments deposited in a large lake bed over tens of millions of years,” NASA’s Jet Propulsion Lab (JPL) reported Monday.

“We are making headway in solving the mystery of Mount Sharp,” John Grotzinger, a Curiosity project scientist from the California Institute of Technology, said in a release. “Where there’s now a mountain, there may have once been a series of lakes.”

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Scientists studying Mars have been trying to figure out why this mountain rests in a crater. Its layers, which JPL says alternate between deposits from lake, river and wind, indicate an evaporation-refill cycle never before witnessed up close on the Red Planet — and a much larger body of water that stayed around for longer. “If our hypothesis for Mount Sharp holds up, it challenges the notion that warm and wet conditions were transient, local or only underground on Mars,” JPL’s Ashwin Vasavada, Curiosity deputy project scientist, said in a news release.

Almost exactly one year ago, Curiosity discovered evidence of fresh water on Mars, enough to “generate clay minerals — and possibly support life — more than 4 billion years ago,” JPL reported in December 2013. At that point, it was the best evidence provided of long-lasting water on Mars, according to The Washington Post.

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“Scientists had announced ... that they’d found signs of an ancient, freshwater lake within Gale Crater, but the new reports provide a much more detailed analysis, including the first scientific measurements of the age of rocks on another planet,” The Post reported last year. “The research suggests that Martian winds are sand-blasting rock outcroppings and creating inviting places to dig into rocks that may retain the kind of organic molecules associated with ancient microbes.”

Curiosity will continue to ascend Mount Sharp. As it does, the rover will gather more information about the mountain’s layering and perhaps shed more light on the water there. To date, no modeling has shown warm enough conditions for a stable water source.

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The ESO 3.6-meter telescope at La Silla observatory in Chile, during observations. (ESO/S. Brunier)