This picture shows the canyon of Nanedi Vallis, one of the Martian valley systems cutting through cratered plains in the Xanthe Terra region of Mars. The picture covers an area 9.8 km by 18.5 km (6.1 mi by 11.5 mi). The canyon is about 2.5 km (1.6 mi) wide. Rocky outcrops are found along the upper canyon walls; weathered debris is found on the lower canyon slopes and along the canyon floor. The canyon shows features that suggest it formed from a combination of collapse and the continuous flow of liquid. The Mars Orbiter Camera (MOC) took the image on January 8, 1998, during the 87th orbit around Mars by the Mars Global Surveyor spacecraft.