Curiosity Rover Eyes Towering Sand Dunes on Mars (Photos)

NASA's Mars rover Curiosity has captured some spectacular new photos of big, active sand dunes on the Red Planet. The new images depict the dark Bagnold Dunes, which Curiosity has been studying for about 6 weeks in history's first up-close investigation of extraterrestrial sand dunes. "The mission's dune-investigation campaign is designed to increase understanding about how wind moves and sorts grains of sand, in an environment with less gravity and much less atmosphere than well-studied dune fi