The Tempe Fossae are a group of troughs in the Arcadia quadrangle of Mars, located at 40.2° north latitude and 71.4° west longitude. They are about 2,000 km long and were named after an albedo feature at 40N, 70W. The term "fossae" is used to indicate large troughs when using geographical terminology related to Mars. Troughs, sometimes also called grabens, form when the crust is stretched until it breaks, which forms two breaks with a middle section moving down, leaving steep cliffs along the sides. Sometimes, a line of pits form as materials collapse into a void that forms from the stretching. See also Fossa (geology) Geology of Mars HiRISE References Valleys and canyons on Mars Arcadia quadrangle