This is a split panel comparing a section of Arizona's Grand Canyon on left against a section of Mars' Nanedi Valles on right. Nanedi Valles is located in the Lunae Palus quadrangle of Mars. The northern part of the Nanedi Valles image shows a river once cut through it, similar to the one flowing through the Grand Canyon. Although this section of Nanedi Valles is nearly 2.5 km in width, other portions are at least twice as wide. Slight morphologic differences between the two canyons are attributable to the great age differences between the regions and the correspondingly higher degree of erosion on Mars.