“A man’s reach should exceed his grasp, or what’s a heaven for?” wondered Robert Browning. But what can we say of a filmmaker who reaches for the skies and thuds haplessly back to Earth, clutching fistfuls of stale air?

“Prometheus” poses the biggest questions science fiction can ask – and answers none. As a prequel to “Alien,” it’s clumsy revisionism. As storytelling, its simplistic characters and ludicrous situations would embarrass a ninth-grader shooting a short film on a digital phone. Not one of its alleged revelations has the power to surprise.

It’s handsome enough; director Ridley Scott hasn’t lost the keen eye he acquired shooting commercials more than 40 years ago, and the 3-D works unusually well. But it’s a pale gloss on “Alien,” that extraordinary work of art, by an ambitious but tired man who’s mumbling platitudes.

Once again, we are aboard a spaceship whose mission conceals a secret, unwholesome purpose decreed by a corporate head (Guy Pearce, badly made up as an old man).

Once again, the captain (Idris Elba) is an easygoing cowboy with no clue why he’s really landing on a potentially deadly planet. Once again, his second-in-command is a tall, no-nonsense, de-feminized woman (Charlize Theron).

And so it goes, through the familiar pattern: An android (Michael Fassbender, who gives the lone first-rate performance) seems helpful but has a hidden agenda. Bickering crew members declare their interest in money rather than science – even though they are scientists. A doctor dies quickly and horribly after an infection. Instead of a roomful of eggs containing alien octopi, we get a roomful of egg-sized canisters containing fluid that yields a different kind of face-grabber.

Scott and writers Jon Spaihts (“The Darkest Hour”) and Damon Lindelof (“Cowboys & Aliens”) leave us hanging from the very first scene. A huge bald creature, nearly human in design but clearly alien, drinks a black fluid. It destroys his DNA (a beautiful sequence shot inside his bloodstream by cinematographer Dariusz Wolski), and he breaks into pieces. Who and where is he, and why is he drinking this poison? These, like many other queries, are never resolved.

Next we’re with two researchers (Noomi Rapace and Logan Marshall-Green) who discover that aliens came to Earth millennia ago and left paintings on caves and rocks, directing us to their home. These two head the expedition that makes up the rest of the story, hoping to find our “makers,” and locate aliens on this distant world whose DNA duplicates ours. (They’re hairless, gigantic and opaque-eyed, but the DNA matches precisely.) Alas, they don’t like us now.

Characters act like morons, approaching fatal encounters with the trusting smiles of simpletons. Nobody thinks twice about holding a hissing snake up to his face or opening the ship’s door to a crew member who now crawls like a spider, his arms and legs bent backward under him.

If the film’s philosophy had some weight, maybe one could forgive the narrative lapses, the slack characterization, the superhuman feats performed by ordinary people with crippling injuries.

But Scott and his writers dither about God and religion and can’t make up their own minds. Are these aliens our makers or not – and, as someone asks, wouldn’t they have makers, too? Heaven is whatever you believe it is, we’re told; perhaps that explains why a character, planning to kill another, removes a crucifix from her neck, as if to leave her defenseless before evil.

It’s important for filmmakers to wrestle with big topics and interesting to see them do so in a genre that traditionally hasn’t cared much about deep philosophy. But if you name your movie after the titan in Greek mythology who stole fire from the Gods and shared it with mankind, you’d better cast a lot of light. “Prometheus” leaves us in the dark.