From a pet dog that looks suspiciously like the Alien xenomorph to nods to 2001: A Space Odyssey , the film is a treasure trove of sci-fi homage. The Voice Cast
With the help of a young resident named Lem, Chuck must evade a paranoid military and a mad scientist to reach his orbiting command module before it leaves without him. Amazon.com Characters and Cast Planet 51 Movie Review | Common Sense Media Planet 51