Grand Canyon, meet your match—and then some. Mars's Valles Marineris (shown in a false-color composite picture released October 22 by the German Aerospace Centre) is the largest canyon system in the solar system.
Stretching across the equatorial Martian highlands for some 2,485 miles (4,000 kilometers), Valles Marineris yawns 124 miles (200 kilometers) wide and up to 6.8 miles (11 kilometers) deep. Earth's 1.25-mile-deep (2-kilometer-deep) Grand Canyon could easily fit into one of Valles Marineris's smaller side valleys.
Another measure of the Martian canyon's magnitude: It took 20 images from the High Resolution Stereo Camera (HRSC) aboard ESA's Mars Express spacecraft to represent Valles Marineris in glorious false color (as pictured above).