NASA rover studies geology of Mars’s crater

Nature : NASA’s Curiosity rover, which landed on Mars last August, is headed toward the center of Gale Crater to study a 5-km-high sedimentary mound called Aeolis Mons. Scientists want a closer look at the mound, informally called Mount Sharp, to try to determine whether it was formed by water or by wind. Because the mound’s base contains clay and sulfate minerals, which require water to form, Dawn Sumner of the University of California, Davis, and colleagues believe Gale Crater could have once contained a lake. However, high-resolution images taken from NASA’s Mars Reconnaissance Orbiter have led Edwin Kite of Caltech and his colleagues to propose that the mound was formed by dust blown into the crater. They say the images show that the mound’s sediment layers are tilted rather than flat, which indicates the material was windblown rather than laid down by deposition in standing water. The researchers hope to settle the question when Curiosity arrives at the base of Mount Sharp in 2014 and its cameras image the mound up close.