Sweeping Panorama of Chasma Boreale on Mars
Image: Chasma Boreale on Mars
“Chasma Boreale, a long, flat-floored valley, cuts deep into Mars’ north polar icecap. Its walls rise about 4,600 feet, or 1,400 meters, above the floor. Where the edge of the ice cap has retreated, sheets of sand are emerging that accumulated during earlier ice-free climatic cycles. Winds blowing off the ice have pushed loose sand into dunes and driven them down-canyon in a westward direction.”
http://spaceref.com/onorbit…