image: The white arrows point to a location on the brink of this dune at 84°N, 233°E that had no alcove in the first year of HiRISE operation (MY29) and experienced sublimation activity (middle), which resulted in the new alcove and fan (with total length of 120 m) in MY30. The layer of new material forming the apron is very thin; the original ripples have not been completely buried. This image relates to an article that appeared in the Feb. 4, 2011, issue of Science, published by AAAS. The study, by Dr. C.J. Hansen of Planetary Science Institute in Tucson, Ariz., and colleagues was titled, "Seasonal Erosion and Restoration of Mars' Northern Polar Dunes." view more
Credit: Image courtesy of <i>Science</i>/AAAS