Entertainment

The atmosphere’s all wrong on ‘Planet 51’

As fresh as the latest issue of The Saturday Evening Post, “Planet 51” occupies the same comedy galaxy as Planet Andy Rooney. “Singin’ in the Rain” references? John Glenn? Cold War duck-and-cover drills? What time capsule yielded this script?

This animated spoof of ’50s alien-invasion movies takes place on a planet populated by avocado-colored critters that combine the cuddliness of your average iguana with the warmth of polyurethane. At least your kids won’t be begging to go to the toy store afterward.

The creatures live in a “Back to the Future”-ish, ’50s-styled world in which the hovercraft look like mid-century American muscle cars and the movies are about invading alien men — “Humaniacs.”

American astronaut Chuck Baker (Dwayne Johnson, whose voice is blandness on steroids) lands on the planet offering warmed-over Buzz Lightyear shtick (posing heroically, plotting wacky schemes). He takes things to inanity and beyond, supplying humorless pop-culture name-checking where the jokes should be, e.g., “Do you have any frappuccino?” and “In space, no one can hear you scream.”

Watching Chuck try to amuse the aliens by quoting from “The Right Stuff” and “Star Wars” is bad enough; the quotes from “The Terminator” don’t even make sense, nor could I figure out why the movie stops to allow Chuck to boogie to a Muzaked, redacted “Greased Lightning.”

Chuck’s mission (to get back to his spaceship within three days) keeps getting interrupted by, say, his giving tango lessons to a friendly alien nerd named Lem (Justin Long, another vocally undistinguished actor) who’s thinking about maybe someday asking out the girl next door (Jessica Biel).

Their dull but chaste relationship is at least free of the weird inappropriateness of a few scenes. A buddy of Lem’s, terrified of the human invader, hands Lem a cork for self-defense in case the astronaut’s interested in body-cavity exploration. Later there will be a joke about a naked man and the strange place where his “antenna” is located.

Also hanging around soaking up screen time are some hippie aliens (their hovercraft is a VW bus, complete with clouds of interior smoke and guitar-strumming protesters) and Chuck’s dog-size robot probe, which skitters around collecting rocks and failing to be as endearing as Wall-E.

Led by a paranoid Dr. Mengele-like scientist (John Cleese) and an equally hostile general (Gary Oldman), the green men threaten to crack open Chuck’s brain and that of anyone who has been contaminated by close contact with him, thus presumed to be a “zombie.”

The jokes are far too weak for adults or children, at least on this planet, while the satirical subtext that is the sole point of potential interest is a jumble.

“Planet 51” at first mocks the idea that these peaceful, ordinary aliens with their barbecues and picket fences are anything to fear, then presents some of the little monsters as scary and violent little creeps who indeed want to do harm to anything they don’t understand. Yet the moral at the end is that we should all be more tolerant of different cultures.

Is that really true, though, if the culture you’re trying to tolerate is trying to open your skull with a circular saw?

kyle.smith@nypost.com