Sand Dunes on Mars (IMAGE) California Institute of Technology Caption This is a perspective view of Nili Patera dune field: The HiRISE image has been draped over a digital elevation model of Mars. Colors correspond to the amplitude of the ripple's displacement extracted by image correlation between two HiRISE observations separated by 105 days. Cool colors (blue) correspond to less than 75 cm of displacement whereas warm colors (red) correspond to 4.5+ meters. Credit California Institute of Technology Usage Restrictions Credit required License Licensed content 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.