Ancient Lakebed and Mars: A Long-Lived Lake Supported Life?

Cold, dry Mars has an 18-square-mile salt flat. That's pretty electrifying news, and it likely means that a habitable body of water existed at that spot, University of Colorado, Boulder researchers reported recently in the journal Geology. 

That dry bed of what is likely a former lake is about the size of the city of Boulder, Colorado, and lies in the Meridiani region near the landing site of the Mars Opportunity rover. Such large-scale deposits, like the one in Utah at Bonneville Salt Flats--which is about 46 square miles--are usually evidence of evaporated bodies of water, as a release said.

The researchers' digital terrain mapping and mineralogical analysis of the area show that the former lakebed is no older than 3.6 billion years old--more recent than scientists previously thought was possible for Mars to have the warmth to sustain extensive planet-wide surface water, according to the release. The general thought is that the solar system formed about 4.6 billion years ago.

"This was a long-lived lake, and we were able to put a very good time boundary on its maximum age," said Brian Hynek, a research associate at the Laboratory for Atmospheric and Space Physics (LASP) at CU-Boulder, said in the release. "We can be pretty certain that this is one of the last instances of a sizeable lake on Mars."

Not only was the area likely a body of water, it was probably only about 8 percent as salty as Earth's oceans; for that reason, it might have been able to support microbial life, scientists estimated in the release.

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