This weekend, two movies take you to the stars in such opposing ways, it feels like an ideological dogfight. Dare we call it "Star Wars"?

One is "Magnificent Desolation: Walking on the Moon 3D," a 41-minute Imax film that salutes -- and reenacts highlights from -- the Apollo missions to the moon between 1969 and 1972. It's all oohs and ahs, thanks to the National Air and Space Museum's 65-foot screen, pristine Imax images and those 3D glasses. This is the big-top approach to space appreciation: a gee-whiz tribute to moon landings, as crew-cut demigods (the real ones and reenactors) bound weightlessly through the lunar dirt like pneumatic lambs.

The audience feels as though it's doing the moonwalk, as it were, with Neil Armstrong and Buzz Aldrin at that historic July 20, 1969, landing. They rub spacesuit-padded shoulders with the other 10 astronauts who made the trip, including Alan Shepard, Edgar Mitchell, Dave Scott and Jim Irwin.

The other film is "A Sidewalk Astronomer," a 78-minute documentary screening at the Cinema Arts Fairfax about John Dobson, a wizened eccentric in a white ponytail who has made a life of popularizing astronomy. We see him holding court on sidewalks and inviting passersby to gaze at the planets through his cannon-size telescope (whose Dobsonian mount he invented).

Dobson's sheer charisma provides the movie's emotional upthrust, though hindered somewhat by the documentary's cut-and-dried style and low-end production values. He's a charmer, a lowercase visionary who seems patient enough to tap every stranger on the shoulder and engage him or her in the glory of space. In a lilt that sounds Irish, English and perhaps alien, he regales them with facts, pithy observations and playful conundrums about the great beyond. With deceptive casualness, he pokes at sacrosanct scientific assertions about time, energy and space. The great questions will be answered, he declares, when religious mystics (from Vedanta followers to fundamentalist Christians) and scientists stop ideologically separating themselves and converge in their thinking. He begs people to look beyond their normal lives and dare to ask the seemingly unanswerable.

"If you don't ask questions," he tells a gathering of listeners, "you're dead." They laugh and raise their hands.

In big-screen entertainment terms, "Magnificent Desolation" is, hands down, the winner. Yet it doesn't ask you to do more than appreciate Our Men of the Space Program. The film is sponsored by the military-industrial complex -- a partnership of NASA and Lockheed Martin -- and it's narrated by a Hollywood powerbase that includes Tom Hanks and Morgan Freeman. Its sensory wonders are temporary; you toss them into the same receiving bin used to collect the 3D glasses.

"Sidewalk Astronomer," which lures you into Dobson's mental universe, is a wonderful portrait of an intellectually tireless seeker. But we're delving into someone's soul; we're taking an inspirational intra-voyage.

Neither movie feels transformational enough. They won't be remembered much beyond this month, let alone register a place in the pantheon of outer-space extravaganzas such as Stanley Kubrick's "2001: A Space Odyssey," Ridley Scott's "Alien" and, yes, "Star Wars." Those movie journeys don't just tell a compelling story; they transport us right out of our terrestrial bucket seats and into the limitless mystery that spreads so unfathomably beyond us. We do want to get home safely, though.

Remember the brilliant poster ad for "Alien" -- "In space, no one can hear you scream"? In eight words, it told you everything. Maybe what we're ultimately looking for is a concise evocation of space. And sometimes the smaller-scale observations of one man and his telescope can be more compelling than an army of technicians trying to rebuild the moon.

"Magnificent Desolation," left, makes the most of the Imax format in its real and re-created footage of moonwalkers, but the documentary "A Sidewalk Astronomer" has a more compelling centerpiece in John Dobson, above.