Swiss Cheese and Dust Devils: 7 High-Resolution Shots of Surface Activity on Mars [Slide Show]
The Red Planet is frigid and possibly sterile, but its surface still sees plenty of action
![Swiss Cheese and Dust Devils: 7 High-Resolution Shots of Surface Activity on Mars [Slide Show]](https://static.scientificamerican.com/sciam/cache/file/C68C39AD-1038-45B9-B5D3EFD2ECCDEF5F.jpg?w=590&h=393)
Swiss Cheese and Dust Devils: 7 High-Resolution Shots of Surface Activity on Mars [Slide Show]
- SPILLAGE: Before HiRISE scientists discovered recurring slope lineae in 2011 Martian gullies were perhaps the most convincing evidence for flowing liquid water on the Red Planet. The photograph above, taken in 2010, highlights in blue the areas within one system of gullies where surface material has eroded away or been deposited in the preceding year... NASA/JPL/University of Arizona
- TWISTER: The HiRISE camera snapped this shot of a towering dust devil crossing the northern hemisphere’s Amazonis Planitia in March 2012. By measuring the dust devil’s shadow and the angle of solar illumination, planetary scientists determined that the structure is some 20 kilometers tall, including the loose dust clouds atop the twister... NASA/JPL/University of Arizona
- QUICKSAND: The HiRISE camera snapped this photo of sand dunes in Nili Patera, an ancient volcanic caldera near the Martian equator, in 2012. That same year a group of researchers published a study in Nature showing that the windblown Nili Patera dunes advance rapidly, at rates comparable to Earthly sand dunes in Antarctica... NASA/JPL/University of Arizona
- HOLEY CAP: Mars’s south pole features an ice cap composed of both water ice and frozen carbon dioxide. In some places patches of carbon dioxide have sublimated into gas and escaped into the atmosphere, leaving behind odd-shaped depressions that lend such regions their colloquial description: “Swiss cheese terrain.” The Mars Reconnaissance Orbiter and its predecessors have documented rapid changes in these Swiss cheese depressions, some of which expand by a few meters per Martian year... NASA/JPL/University of Arizona
- STREAKERS: Another animated gif of Newton Crater shows more RSL popping up in the southern hemisphere’s warmer seasons. The dark RSL are most prominent in the fourth frame of the gif (labeled “ESP_022689_1380”), taken during early to mid-summer, toward the top of the photograph... NASA/JPL/University of Arizona
