Mars
By NASA
This is a real portrait of Mars, stitched together by NASA from images taken by the Viking orbiters in the 1970s. The huge gash running across the lower half of the planet is Valles Marineris, a canyon system so vast it would stretch across the entire United States. If you followed it end to end, it would run about 2,500 miles, making the Grand Canyon look like a scratch by comparison.
That rusty orange color, the reason Mars earned its nickname the Red Planet, comes from iron in the soil that has literally rusted over billions of years. The dark smudges and pale swirls near the top are dust storms and thin clouds moving through the atmosphere. Notice the three faint dark spots lined up on the left side. Those are enormous volcanoes, part of a cluster that includes Olympus Mons, the tallest mountain in the solar system at nearly three times the height of Everest. For a world we have never set foot on, this image lets us see its scars and storms as clearly as if we were floating just above it.