Now this is what these here internets were invented for: Walt Disney's wonderful 1957 science reel Mars and Beyond, preserved for the ages, or until youtube gets bought up by Google or somebody. Say what you will about Walt—he was a friend of science, and this documentary features the state of the art in Martian technology, from the golden age of Wernher von Braun's Marsprojekt. When these kinds of movies work well, they remain fascinating equally for what was right, what was wrong, and what was wrong but still seems kinda right. All of it narrated by the great Paul Frees, whom you will recognize immediately as That Guy Who Narrated All That Stuff.
In six parts: A survey of the post-Ptolemaic universe. A mocking roundup of pop-culture views of Mars that seemed as absurd in 1957 as this movie now seems to us. A primer on evolution that hopefully claims Venus, Earth, and Mars exist in a "temperate zone favorable to life: this golden zone" where "man could survive on Mars with some kind of moderate protection." A history of Mars observations, modern enough to dismiss the canal theory but not modern enough to avoid trumpeting an illusory and now-forgotten "green area the size of Texas;" also featuring some vaguely accurate comments by Dr. E.C. Slipher, who looks exactly like what a scientist should look like. A zoology of potential life on Mars—from silicon-based life forms to sonic and optical hunters who kill their prey with sound waves and concentrated sunlight, respectively. And von Braun's chef d'oeuvre, a fleet of Earth-based supersaucers that settle Mars by shooting rockets into its atmosphere.
It all came to nothing, and while it's tempting to blame NASA or the end of the space race, it's really the Red Planet itself that let us down. Even the conservative Professor Slipher underestimated how unpromising our nearest neighbor would turn out to be. The idea of colonizing space in any imaginable future looks more and more like the last vestige of the geocentric universe, with its assumption that earth-normal conditions are a default or somehow reproducible on a large scale through hard work and ingenuity. (I caught the really shady libertarian fave Serenity recently, and had to chuckle at that movie's reference to "terraforming, a decades-long process.") In fifty years they'll be laughing at NASA's hopes for establishing a base on Mars.
On a more positive note, I found that picture of Carl Sagan's farting balloon creatures on Jupiter. Who wouldn't breathe a little methane and ammonia for the chance to meet one of these babies (check out the "hunter" making a meal of one of the "floaters" in the lower right corner):