Valley network (Mars)
Videos
Valley networks are branching networks of valleys on Mars that superficially resemble terrestrial river drainage basins. They are found mainly incised into the terrain of the Martian southern highland
Branched valley network in Thaumasia quadrangle, as seen by Viking Orbiter. Field of view is roughly 200 km across.
Part of a valley network near Warrego Valles, seen by THEMIS. Length of image is roughly 50 km.
Finer scale valley networks near Candor Chasma, seen by HiRISE (click to zoom). Field of view is roughly 3.5 km across. Surface the valleys are cut into appears to be eroding back.
The Eberswalde delta, seen by MGS. Note the meanders with cutoffs, now seen in inverted relief.
Water on Mars
Videos
Although very small amounts of liquid water may occur transiently on the surface of Mars, limited to traces of dissolved moisture from the atmosphere and thin films, large quantities of ice are presen
Mars contains water, though mostly as subsurface permafrost. Surface water is readily visible at some places, such as the ice-filled Korolev Crater, near the north polar ice cap.
Mars canals illustrated by astronomer Percival Lowell, 1898.
History of water on Mars. Numbers represent how many billions of years ago.
Mars meteorite ALH84001.