The science team from the HiRISE camera on the Mars Reconnaissance Orbiter wanted to take another look at a region of icy sand dunes on Mars to look for seasonal changes as spring is now arriving on the Red Planet’s northern hemisphere. But the view was obstructed by clouds, creating this unusual hazy view.
“This happens occasionally. We’ve found that weather forecasting on Mars is just as challenging — if not more — than on Earth,” said HiRISE team member Candy Hansen, who I nabbed in the hallway during the Lunar and Planetary Science Conference today, to ask about this unique image. “The clouds are likely made of water ice crystals, and the dunes have a coating of CO2 ice that is just starting to sublimate away as the Sun’s rays are getting stronger in this region.”
Hansen said these are dark barchan, or crescent-shaped dunes. During the winter, this region was completely covered with carbon dioxide ice, but now just the the tops of the dune have ice; also visible are what looks like white cracks, which is ice protected in shallow grooves on the ground. HiRISE will likely check back on this region later during the Martian summer to provide the science team with a seasonal sequence portfolio of images of the region, a benefit of having a mission in orbit for several years. MRO and HiRISE are workhorses, having been in orbit since March of 2006.