This is a really funny episode. Everyone goes back in time. It's a classic.
Zoidberg, Fry, Leela, Bender and the professor go in the spaceship to watch star turn into a supernova. Fry goes to make popcorn in the microwave. He puts metal into the microwave at the same time as the star turns into a supernova. They get sent back in time to July 9th 1947. There is no global positioning system so they crash. Bender doesn't put his seat belt on and he flies out the windshield and breaks into hundreds of pieces. They land in Roswell, New Mexico. Zoidberg is picking up the pieces of Bender when the Roswell army captures them. they think that Bender is a spaceship and they think Zoidberg is an alien. A bunch of funny things happen with Zoidberg. Meanwhile Leela fixes the ship. She fixes everything except for microwave. The professor figures out that they have exactly 24 hours to get a microwave or else they can't get back to the future. Leela and the professor looks for one, but they can't find one. They weren't invented yet. Fry finds his grandfather Enos. He is in the army. He is about 30 at the time. Fry tries to save him from everything because if he dies, then Fry will too. Fry and Enos go to a restaurant and Enos's girlfriend is a waitress there. Her name is Mildred. Mildred is also Fry's grandma. Fry doesn't want to die so he locks Enos in a house in the middle of the desert. The house was used for a bomb test, but Fry didn't know that. Enos died, but Fry didn't. He figured out that Enos wasn't his grandpa and Mildred isn't his grandma so Fry has sex with Mildred. Then the professor explains to Fry that he is his own grandfather. Fry is shocked. Leela finds a microwave satalite dish. They steal it and steal Bender's body back and they get Zoidberg back. As soon as they are about to go back to the future, Bender falls off the ship. They couldn't turn around or they couldn't go back to the future. Once they get back to the future, Fry has an idea. He goes to Roswell which is just a desert now. He uses a metal detector and digs up Bender. He was buried in the ground for 1000 years. Everything is back to normal, except Fry is his own grandfather.
I give this episode a 9.4 out if 10.