The Unearthly Landscapes of Mars; June 2003; Scientific American Magazine; by Arden L. Albee; 10 Page(s)

Captain John Carter, the hero of the adventure novels of Edgar Rice Burroughs, was a gentleman of Virginia and an officer of the Confederacy. Impoverished after the Civil War, he went looking for gold in Arizona and, while being chased by Apache warriors, fell and struck his head. He returned to consciousness on an arid planet with twin moons, populated by six-legged creatures and beautiful princesses who knew the place as "Barsoom." The landscape bore an uncanny resemblance to southern Arizona. It was not entirely dissimilar to Earth, only older and decayed. "Theirs is a hard and pitiless struggle for existence upon a dying planet," Burroughs wrote in the first novel.

In science as well as science fiction, Mars is usually depicted as a version of Earth in its extreme-smaller, colder, drier, but sculpted by basically the same processes. Even well into the 20th century, many thought the planet had flowing water and proliferating plants. The resemblance to Earth fell apart when spacecraft in the late 1960s revealed a barren, cratered world, more like the moon. But it quickly returned with the subsequent discoveries of giant mountains, deep canyons and complex weather patterns. The Viking and Mars Pathfinder images from the surface look eerily Earth-like. Like Burroughs, researchers compare the equatorial regions of Mars to the American Southwest. For the polar regions, the model is the Dry Valleys of Antarctica, a frozen desert in a landscape of endless ice.