* COMING SOON ON THEATRE *
The story starts with two teenagers being attacked by a "humaniac," a horrendous one-eyed monster that comes down to the planet to turn everyone into zombies and take over the world. Then it is revealed that this is a mere movie, though the plotline resembles classical 1950s science fiction films.
Outside the theater is Planet 51, a world populated by little green aliens that live in a society similar to 1950s earth. Lem (Justin Long) is a teenage alien who has just gotten a job working at the local planetarium museum, and everyone in his neighborhood is excited about it. His best friend is Skiff (Seann William Scott), a geeky alien teen who works at the local comic book store, and is a huge fan of the "Humaniacs" films.
When Lem gets home, he asks his next door neighbor and friend, Eckle (Freddie Benedict) about Neera (Jessica Biel), a long-time crush of his. His family is holding a barbecue with the neighbors, so Neera is there, but when Lem attempts to ask her out, he keeps being interrupted by Neera's hippie friend, Glar.
Meanwhile, a mysterious spacecraft pulls into orbit, sending out a blinking red signal. Down on the planet, under a hidden army base called "Base 9" (the aliens' version of Area 51), there is a basement filled with artifacts from earth. One of them "wakes up" from the signal, and is a wheeled probe with an AI named "Rover." It breaks out of the basement and escapes, off to perform its primary mission: find astronaut. It's secondary mission is to collect rocks, (similar to Wall-E gathering garbage for compacting). Due to Rover's escape, the army becomes very suspicious of what's going on.
Meanwhile, just as the barbecue starts, a spacecraft similar to the lunar module touches down right in Lem's backyard. The astronaut (Dwayne Johnson), Charles 'Chuck' Baker, emerges, humming the theme from 2001: A Space Odyssey. As Chuck plants the flag, he's startled to step on an alien "rubber ducky" someone left on the ground. Everyone stares, and Chuck attempts to get back into his module - but Eckle is in his way, eager for an autograph. Chuck ends up running about, shocked at the revelation that this is an inhabited planet. At one point, he gets hit by the mailman's scooter in the middle of the street and goes flying past the moon (in reference to E.T.). He goes into hiding soon after, while the army immediately arrives on the scene.
General Grawl (Gary Oldman) is at the head of the investigation, and consults Professor Kipple (John Cleese) on intelligence about the "alien invader." The army then quarantines the area and has locals start a local "civil defense" force to protect the citizens from becoming "zombies."
Up at the planetarium, Lem discovers Chuck hiding there, and both are surprised to learn that they speak the same language. Chuck introduces himself, and he's eager to get off the planet and get back home in time for the Nickelodeon Kid's Choice Awards. It's then that Lem realizes the "alien" is no threat and decides to help him, though it costs him his job and a near arrest at the hands of the army. It soon becomes apparent that Chuck can't go anywhere near his module (which the aliens repeatedly call a "flying saucer"), so Lem hides him in his room for the night.
In the meantime, Rover locates Chuck, though he has to sneak past the soldiers patrolling the neighborhood. Chuck is very happy to see the robot when they reunite, though he tells Rover that the probe was not helpful because it only took pictures of rocks and not the little green men living on the planet. (This is what led to the misinformation that the planet was uninhabited). Skiff and Eckle are let in on Lem's secret, as are two soldiers who believe that they are being mind-controlled by Chuck.
Skiff and Lem decide that the people need to see Chuck is harmless, and the only way to do that is by having him talk to the press (who have been copiously helping feed the fear of the citizens). So they have the two soldiers smuggle Chuck to the comic book store and hide there while Lem goes to get the reporters. Before Lem leaves, he asks Chuck to help him with some advice regarding Neera; Chuck attempts to use what he calls "the right stuff," to show Lem how to woo her. In his attempt to find the reporters after, Lem has to face Neera, whom he had a falling out with when she and her friends (including Glar) were protesting the army's treatment of the alien and his craft. Chuck's advice in winning her back doesn't work well, and there is still friction between the two of them.
Back at the comic book store, Chuck is playing with Eckle, using the whole alien invader theme everyone keeps talking about, while the "mind-controlled" soldiers watch and Skiff bonds with Rover. At one point, Planet 51's signature "rock rain" starts falling, and Rover becomes ecstatic, since collecting rocks is what he does, and he starts "dancing" in the streets (in reference to Singin' in the Rain).
Unfortunately, Lem and Skiff's plans for peacefully introducing Chuck backfire when the reporters discover him in the bookstore and secretly film him quoting lines from Star Wars and The Terminator. The broadcast throws Lem's whole world into chaos, and he, Chuck, and his friends barely escape the soldiers hounding them through town. They hide Chuck in Lem's room again, though it's apparent that things have become decidedly worse. The army sets up barbed wire fence around the module, and Lem is angry at Chuck for turning his life upside down.
Things get even worse when General Grawl decides to set up a base in Lem's home. Lem and his friends just barely escape with Chuck before the general and his men search the kid's room. The group somehow manages to sneak Chuck into the planetarium, and while there, Chuck admits to Lem that he never had "the right stuff." He says that Lem was the one who had "the right stuff" all along, making risks and sacrifices just for a stranger. Chuck also shows Lem the star that Earth orbits, and how the universe is so much bigger than Lem had thought.
The next morning, the army brings in vehicles to take Chuck's module to a secret location. Even the press isn't allowed to tell where the spacecraft is going.
Lem and Skiff are at a loss for getting Chuck back into his craft, but then they get an idea from the comic book store. The very next night is opening night for a new "Humaniacs" movie, and there's a costume contest going on. Lem, Skiff, and Chuck disguise themselves as costumed fans, though Chuck gets accidentally pulled into the contest. As a cover for the army soldiers patrolling even the convention, Lem and Chuck go along with the contest. Chuck then introduces some new music as part of the contest and teaches Lem right on the spot how to dance. Things go well until Rover comes on the scene, and the aliens at the contest freak at the sight of him. Chaos ensues, and army soldiers are unmasking kids everywhere, since they now think the "alien" is among them. General Grawl and Professor Kipple are there, and when the general points out that the alien is wearing a "uniform," compared to the other costumed fans, Chuck's United States Flag insignia is a dead giveaway.
Chuck is captured and unmasked for all to see, and the General makes a great show of his disgust for the "alien." When Lem tries to defend Chuck and keep him from being taken away, General Grawl merely labels him as a zombie, and Professor Kipple announces that he will dissect both their brains. Chuck is not willing to drag Lem into this, so he pretends to "release" Lem from his control, and the crowd believes it. Both Chuck and Rover are locked in armored vehicles, and when the General makes it clear to Rover that he intends to take him apart, piece by piece, the little robot responds like a dog wetting itself in fear, only with oil. They're taken away, and Lem is proclaimed a hero of the community.
At Base 9, General Grawl attempts to get some answers out of a handcuffed Chuck, warning that if he tries taking over the minds of the soldiers in the room, a chain reaction will set off and everyone will shoot at each other and possibly be electrocuted. Chuck accidentally hits a button and sets off said chain reaction, though he's not at all affected by it. General Grawl mistakes this as resisting his demands, and allows Professor Kipple to have a go at Chuck's brain.
Lem gets his job back at the planetarium and gets to speak on tv, but he cannot truly accept the honor. He feels terrible about Chuck and decides to do the right thing. He hotwires a car, and at the same time Neera comes to talk to him, admiring what he's doing. Neera, Skiff, and Eckle join Lem as they go off to rescue Chuck. However, not only do they not know where the army took him, but they feel they can't really find the astronaut without Rover, who had also been taken by the army. But luck is on their side when the little robot shows up on the edge of town, revealing that he unscrewed all the bolts holding the armored vehicle he was in together.
They have Rover act as a bloodhound, sniffing out Chuck's trail, leading the kids to an abandoned gas station in the middle of the desert. They explore, and Skiff sees a "Coca-Cola" bottle in an old fridge, though when he tries to take it, it's actually a hidden trigger that opens up the entrance to Base 9. Lem has Glar distract the soldiers guarding the base with his protest group while they sneak in.
In a laboratory, Chuck is strapped to a table while Professor Kipple gets ready to take his brain out. Luckily, Lem and his friends break in through the ceiling, using Rover to scare away the scientists, technicians, and guards. They free Chuck and immediately set off alarms.
Rover helps the group find Chuck's module, which has been placed in a hangar, but General Grawl stops them. He warns that if the "alien" attempts to leave, the entire hangar will blow, and reveals that the place is rigged with bombs. Lem tries reasoning with him, when in fact it's a distraction to set off the bombs and use the confusion to help Chuck escape. Most of the soldiers flee the firestorm, and the General is knocked out amidst the falling debris. Lem, Neera, Eckle, Skiff, and Rover all get into the module, but Chuck decides he can't leave the General to die, and rescues him from the fire.
To escape the growing firestorm, Chuck pilots the ship up into orbit around the planet, allowing the alien kids to see what space is really like. Kiff, Eckle, and Rover enjoy the weightlessness, General Grawl realizes that Chuck is friendly and hasn't turned him into a zombie, and Lem finally gets to ask Neera out on a date.
Chuck pilots the module back down to the planet's surface, and although the army is ready to shoot as everyone walks out, the General stops them and explains that Chuck is with him. Finally the aliens of Planet 51 get to see that Chuck is harmless and never intended to hurt anyone. He lets Rover stay and become Skiff's pet, and says goodbye to everyone.
As the module is leaving, it's revealed that one of the alien "dogs" snuck on board.
To watch this trailer , click this link :
http://www.youtube.com/watch?v=YqsANwvBYpA
