Early in Disney's IMAX documentary Roving Mars, as the camera pans over the surface of the storied red planet, I thought I was looking at actual footage taken during a recent NASA mission. It quickly became obvious that the scenes were computer-generated, but it's probably the best looking CGI I've ever seen. Computerized special effects rarely look as good as old-fashioned miniatures, but the Mars scenes in Roving Mars are astonishing.

The film follows the production, launch, and successful mission of Spirit and Opportunity, the small six-wheeled vehicles which landed on Mars in 2004. Putting a robot on Mars might not be as romantic as sending people to another planet, but the people at NASA's Jet Propulsion Laboratory became deeply attached to their little rovers, which seemed to develop different personalities during the mission. (Spirit, the temperamental first robot, was forced to crawl over Mars for five months to reach the spot scientists wanted to investigate; Opportunity, nicknamed "Little Miss Perfect," landed exactly where NASA wanted.) Even if no astronauts were involved, you can't help being tremendously impressed by what the engineers accomplished - the equivalent of throwing a basketball from Los Angeles into a hoop located in New York, according to one scientist.

I wish I could have seen Roving Mars on a giant IMAX screen, but the film may work even better on DVD - some critics complained that the movie wasn't spectacular enough for IMAX, and the disc contains some interesting special features. There's a making-of documentary featuring extended interviews with some of the NASA scientists who worked on Spirit and Opportunity, and - for historical value - a 1957 Disneyland episode, hosted by Walt himself, showing how people thought about Mars during the Sputnik era.

The computerized images of Mars (based on pictures sent back by Spirit, Opportunity and other spacecraft, according to the producers), accompanied by Philip Glass's haunting score, are the highlights of Roving Mars, but even the footage from earth is pretty interesting in its own right. The filmmakers were allowed access to NASA facilities when the rovers were being built and tested, and some of the less-than-successful test footage made it into the documentary. (If you think it's easy to design a parachute, try designing one for a mission like this.)

Near the end of Roving Mars, a scientist says the first person to walk on Mars is probably in high school - or even elementary school - today. Decades from now, don't be surprised if that lucky person saw this film as a child.