Mars seems dry and dead today, but the more we investigate the planet, the more evidence we find that at one point water flowed freely in at least some places on our neighboring planet.
NASA’s Curiosity rover is still trundling over the red planet’s surface, and its latest data brings scientists to an interesting conclusion. The mountain Curiosity is investigating, Mount Sharp, might actually have been built up by sediments being deposited in a lake bed over tens of millions of years.
“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,” said Ashwin Vasavada, Curiosity deputy project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “A more radical explanation is that Mars’ ancient, thicker atmosphere raised temperatures above freezing globally, but so far we don’t know how the atmosphere did that.”
Mount Sharp, near Curiosity’s initial investigation area in the Gale Crater, stands about three miles high. Curiosity is now checking out the lowest layer of the Mount Sharp, a 500-foot high area called the Murray formation. Investigating the sediments in the exposed rock layers shows evidence of repeated filling and evaporation of a Martian lake.
NASA’s theory is that as the sediment layers hardened and the rock pile slowly built, it was shaped into something that looked mountain-like by wind erosion.
Curiosity will continue its mountaineering mission as it seeks answers.
“The great thing about a lake that occurs repeatedly, over and over, is that each time it comes back it is another experiment to tell you how the environment works,” Curiosity Project Scientist John Grotzinger of the California Institute of Technology in Pasadena said. “As Curiosity climbs higher on Mount Sharp, we will have a series of experiments to show patterns in how the atmosphere and the water and the sediments interact. We may see how the chemistry changed in the lakes over time. This is a hypothesis supported by what we have observed so far, providing a framework for testing in the coming year.”