Valles Marineris - Point Perspective
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Mosaic of the Valles Marineris hemisphere of Mars projected into point 
perspective, a view similar to that which one would see from a
spacecraft. The viewer's distance is 2,500 kilometers from the surface of
the planet. The mosaic is composed of 102 Viking Orbiter images of 
Mars. The center of the scene (lat -7, lon 78) shows the entire Valles 
Marineris canyon system, over 3,000 kilometers long and up to 8
kilometers deep, extending from Noctis Labyrinthus, the arcuate system
of graben to the west, to the chaotic terrain to the east. Many huge
ancient river channels begin from the chaotic terrain and north-central
canyons and run north. Many of the channels flowed into a basin called
Acidalia Planitia, which is the dark area in the extreme north of this
picture. The three Tharsis volcanoes (dark red spots), each about 25
kilometers high, are visible to the west. South of Valles Marineris is
very ancient terrain covered by many impact craters.

Image Processing by Jody Swann/Tammy Becker/Alfred McEwen, using the
PICS (Planetary Image Cartography System) image processing system
developed at the U.S. Geological Survey in Flagstaff, Arizona.