PASADENA, Calif., Feb. 11 (UPI) -- Scientists have long believed that water once flowed freely on Mars, making it place habitable for living organisms. But so far, scientists have only been able to point to ice discovered on the Red Planet as evidence of their theories.
Now there are signs that water may still be flowing on Mars. While the new findings aren't conclusive, NASA scientists have images that suggest the movement of water on the slopes of several Martian mountains.
Images captured by NASA's Mars Reconnaissance Orbiter show dark lines moving down the slopes of these mountains as temperatures on the planet's surface rise. The dark flows, called "recurring slope lineae," or RSL for short, usually indicate the presence of water, but as yet no water has been directly observed.
"We still don't have a smoking gun for existence of water in RSL, although we're not sure how this process would take place without water," said Lujendra Ojha, one of the lead scientists studying the flows.
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NASA scientists are weighing a number of possibilities for what exactly is causing these flowing lines, but all of them involve the presence of water. The leading hypothesis is that this elusive surface water is kept liquid by the presence of salts and irons which lower the freezing point of water.
"The flow of water, even briny water, anywhere on Mars today would be a major discovery, impacting our understanding of present climate change on Mars and possibly indicating potential habitats for life near the surface on modern Mars," said MRO Project Scientist Richard Zurek, of NASA's Jet Propulsion Laboratory in Pasadena, Calif.
[Photo Credit NASA/JPL-Caltech) [NASA]
