As you can see from the image below, Mars has few distinguishing features when viewed from Earth, even with the best telescopes. There are dark and light areas, as well as polar ice caps, but certainly not the clear features that you can see in images from orbiters around Mars. Therefore, we can excuse early astronomers for making mistakes or embellishing their observations. To these scientists searching the sky, Mars was a vastly different world than we know today.
In 1877, Giovanni Schiaparelli, an Italian astronomer, was the first person to draw a map of Mars. His map showed a system of streaks or channels, which he called canali. In 1910, the U.S. astronomer Percival Lowell made observations of Mars and wrote a book. In his book, Lowell described Mars as a dying planet where the civilizations built an extensive network of canals to distribute water from the polar regions to the center of the planet.
Although Lowell's book captured the public's imagination, the scientific community summarily dismissed it because his observations weren't confirmed. Nevertheless, Lowell's writings sparked generations of science fiction writers. Edgar Rice Burroughs of Tarzan fame wrote several novels about Martian societies, including "The Princess of Mars," "The Gods of Mars" and "The Warlord of Mars." H.G. Wells wrote "The War of the Worlds" about invaders from Mars (Orsen Welles' radio play of this book caused a national panic in 1938).
Hollywood has also fueled the public's fascination with the planet in films such as "The Angry Red Planet," "Invaders from Mars" and, more recently, "Mission to Mars" and "Total Recall," a futuristic mega-hit that featured Arnold Schwarzenegger leading dual lives on Earth and Mars.
In the 1960s and 1970s, however, the U.S. Mariner, Mars and Viking missions started sending back images of a very different world from that described by Lowell and his fiction and silver-screen successors. The photos, snapped during flybys of the planet and eventually during the Viking landings, showed Mars as a dry, barren, lifeless world with variable weather that often included massive dust storms that could whip across a majority of the planet. So with thousands of photos as evidence, Mars was confirmed as a rust-colored, desert planet with rocks and boulders, rather than the home of irritable Martians and man-eating plants a la "The Angry Red Planet."
Now, we have extensively mapped the planet's surface with Mars Global Surveyor, sent rovers to bump over its surface and scoop up soil samples, and launched orbiters to observe the planet from space. More missions are in the works. NASA has committed to an extensive program of robotic and possibly human exploration of Mars.
So far these missions have enabled scientists to hazard a theory about how the red planet formed, and the story would actually make a pretty good movie. Read on to learn how solar collisions gave the Earth its next-door neighbor.