Mystery of 'water marks' on Mars FINALLY solved

  • Mystery of 'water marks' on Mars FINALLY solved

Mystery of 'water marks' on Mars FINALLY solved

Those slopes are caused by dry grains of sand flowing downhill, without the help of any water. At the time, NASA thought that was significant evidence that flowing liquid water caused these freakish streaks. However, it does not explain the origin of these numerous flowing features or its gradual growth. Scientists, including those from the University of Arizona in the U.S. and Durham University in the United Kingdom analysed narrow, down-slope trending surface features on Mars that are darker than their surroundings, called Recurring Slope Linea (RSL). They found out that the steaks found on Martian surface were not flowing water but were likely the avalanches of sand and dust.

But this does not mean researchers have completely ruled out water.

Colin added: "We've thought of RSL as possible liquid water flows, but the slopes are more like what we expect for dry sand".

There are still unanswered questions, such as why the streaks appear and vanish with the seasons, and what makes them dark in color. Since liquid water is key for life here on Earth, many thought these unusual lines of flowing water may help support life on the Martian surface.

This HiRISE image cutout shows Recurring Slope Lineae in Tivat crater on Mars in enhanced color. "This new understanding of RSL supports other evidence that shows that Mars today is very dry".

Scientists, however, are optimistic about the RSL as a unique feature of Mars.

NASA's Mars Reconnaissance Orbiter has been orbiting Mars since 2006, completing 45,000 orbits a year ago.

Sand stream found in Martian surface.

It was observed that the RSL had been found only in slopes which were steeper than 27 degrees. If water was involved, the dark streaks would be visible on both steep and shallow slopes.

According to the research, liquid water on Mars would be limited to traces of dissolved moistures from the atmosphere and thin films, which would be challenging to earthly model life.

The new report describes possible connections between these traits and how RSL form. They doubted that if liquid water was to be present on those RSL slopes, then it would have flown to a longer distance on longer slopes.

"Full understanding of RSL is likely to depend upon on-site investigation of these features", says MRO project scientist Rich Zurek of NASA's Jet Propulsion Laboratory in Pasadena, California. That's bad news in the hunt for microbes, unfortunately.