6. Valles Marineris (12°S,64°W)
This image shows the central portion of Valles Marineris. In this region, Valles Marineris actually consists of two troughs that are close together. The linearity of the main segments of Valles Marineris indicates that it is a tectonic feature caused by motions in the mantle of Mars (see slide #14 and Fig. 2a). This is unlike the Grand Canyon on Earth, which was cut by the Colorado River. This image is approximately 475 kilometers across.
From Mars Digital Image Map, image processing by Brian Fessler, Lunar and Planetary Institute, Houston