Flight Into Mariner Valley: Valles Marineris

Valles Marineris, the largest known canyon in our solar system at  2,480 miles long, 125 miles wide and 6 miles deep, "...that’s five times deeper than the Grand Canyon and long enough to stretch across the entire contiguous United States," observes Universe Today in article about Martian canyon, "Valles Marineris: The Grandest Canyon of All." The canyon located along the Martian equator, gets its name from the Mariner 9 Orbiter that discovered it in early seventies.  It's an interesting flight simulation through the gigantic canyon, but did it form through geological processes?