'Plan­et 51' is a galac­tic sized an­i­mat­ed alien ad­ven­ture com­e­dy re­volv­ing around Amer­i­can as­tro­naut Cap­tain Charles "Chuck" Bak­er, who lands on Plan­et 51 think­ing he's the first per­son to step foot on it. To his sur­prise, he finds that this plan­et is in­hab­it­ed by lit­tle green peo­ple who are hap­pi­ly liv­ing in a white pick­et fence world rem­i­nis­cent of a cheer­ful­ly in­no­cent 1950s Amer­i­ca, and whose on­ly fear is that it will be over­run by alien in­vaders...like Chuck! With the help of his robot com­pan­ion "Rover" and his new friend Lem, Chuck must nav­i­gate his way through the daz­zling, but be­wil­der­ing, land­scape of Plan­et 51 in or­der to es­cape be­com­ing a per­ma­nent part of the Plan­et 51 Alien In­vaders Space Mu­se­um.