NASA's Mars Reconnaissance Orbiter has found a very dynamic Mars surface.
ScienceDaily - Images from NASA's Mars Reconnaissance Orbiter show sand dunes and ripples moving across the surface of Mars at dozens of locations and shifting up to several yards. These observations reveal the planet's sandy surface is more dynamic than previously thought.
"Mars either has more gusts of wind than we knew about before, or the winds are capable of transporting more sand," said Nathan Bridges, planetary scientist at the Johns Hopkins University's Applied Physics Laboratory in Laurel, Md., and lead author of a paper on the finding published online in the journal Geology. "We used to think of the sand on Mars as relatively immobile, so these new observations are changing our whole perspective."
While red dust is known to swirl all around Mars in storms and dust devils, the planet's dark sand grains are larger and harder to move. Less than a decade ago, scientists thought the dunes and ripples on Mars either did not budge or moved too slowly for detection.
MRO was launched in 2005. Initial images from the spacecraft's High Resolution Imaging Science Experiment (HiRISE) camera documented only a few cases of shifting sand dunes and ripples, collectively called bedforms. Now, after years of monitoring the Martian surface, the spacecraft has documented movements of a few yards (or meters) per year in dozens of locations across the planet.
