THEMIS Vistas

IN THE GROOVE. Impacts, floods, and tectonic forces have all left traces on Ares Vallis, a Martian outflow channel. This view looks to the northwest, down the scoured channel toward Chryse Planitia. Outflow channels formed when massive floods of water poured out of the ground early in Martian history when the planet likely had a thicker atmosphere and a warmer climate. Scientists estimate the floods had peak volumes many times today's Mississippi River. Tear-drop mesas extend like pennants behind impact craters, where the raised rocky rims diverted the floods and protected the ground from erosion. While Ares Vallis is not the widest or deepest outflow channel, it extends for nearly 1,600 kilometers (1,000 miles). (A 4.4 MB version of the image is available.) Credit: NASA/JPL/Arizona State University, R. Luk (no vertical exaggeration).

To explore Ares Vallis further, check out the THEMIS feature article about this place.