File:Canyon in Terra Sabaea - CRISM - CTX - Flickr - jccwrt.png

A canyon in Terra Sabaea imaged by Mars Reconnaissance Orbiter (MRO) on June 8, 2007. The canyon imaged here is about 40 km (24 mi) wide at its widest point, or about 1.25x the width of the Grand Canyon. It is a graben, a region where the Martian crust has been stretched to form large valleys. This canyon forms an arc shape that follows the shape of the 2300 km wide Hellas Basin, the largest confirmed impact crater in the Solar System. This canyon probably formed as the Martian crust slid inwards to fill the giant hole created by the Hellas impact. If so, it marks the edge of a large slump involving several million square kilometers of the Martian surface.

This canyon is approximately 2 km deep, but was initially much deeper. Terra Sabaea is among the oldest exposed parts of the Martian surface and has been heavily eroded by liquid water that was present early in the planet's history. This erosion has filled much of the canyon's initial depth with sediment. Several remnants of the river systems that carried sediment into this valley are visible as linear branching ridges along the canyon floor. These likely represent hardened riverbed sediments that have resisted erosion better than the surrounding canyon floor materials.

This image combines color data collected by MRO's CRISM spectrometer and CTX camera system to produce a true-color image. This image uses CRISM stamp 616D9.