Mars From Afar
Canyon
In the center of this mosaic of Mars lies the Valles Marineris, the
largest known chasm in the solar system. It stretches over 1,860
miles from west to east, and in places reaches five miles in depth.
(The Grand Canyon, at its deepest, is just over a mile from rim to
river.) Huge rivers once flowed north from the chasm's north-central
canyons to a vast basin called Acidalia Planitia (the dark area in
the top right of the image). To the west of the Valles Marineris you
can see three ancient volcanoes (dark brown circles), each about 15
miles high. This mosaic consists of 102 images from the Viking
Orbiter, and the viewer's distance is 1,550 miles above the surface.