Ridges (image) Brown University Caption Mineral deposits mark subsurface water flow: A photo taken by the Mars Reconnaissance Orbiter shows ridges formed by fossilized subsurface water flow. Orientation of the ridges, mapped by researchers, is consistent with fractures formed by impact events. Credit NASA and Mustard Lab/Brown University Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.