Back to the Future Season 2 Episode 10 My Pop's an Alien Episode Title:My Pop's an Alien.Episode Description:Marty parallel parks the DeLorean outside the store that Jules and Verne are in. As the comet Kahooey is about to pass the Earth's orbit, Biff declares that aliens are coming and causes the residents of Hill Valley to panic. Biff finds a "space craft" behind Doc's oleander bushes – an alien craft he recognizes from 25 years earlier and the last time comet Kahooey appeared. Biff has the military, police and assorted agencies believing that Doc is an alien. With Doc in serious trouble, Marty, Jules and Verne travel back to 1967 to straighten out the mess. Marty and the boys find that Doc has built a flying craft to view the comet and that Biff has mistaken it for an alien space ship. When Marty, Jules, and Verne appear in beekeeper suits and the DeLorean while confronting him, they make Biff promise that he will not say anything about the "visit" from the aliens – now and in the future. Biff promises and Marty, Jules and Verne head back into the future in 1992, early 1993. When they arrive, Doc is fine and Biff is trying to peddle some cheesy "alien" souvenirs without much luck. Bill Nye Segment: Examining optical illusions.