The Comet Polarization is the twenty-first episode of the eleventh season of The Big Bang Theory.
While looking through Raj's telescope, Penny discovers a comet, leading to tension between them. In addition, Stuart's comic book store becomes popular, leading to Stuart hiring a new assistant manager, Denise, and Howard and Bernadette try to plan a date night.
Howard, Raj, Penny, Amy, Sheldon, and Leonard are up on the roof, using Raj's telescope to check out planets. Raj feels that his telescope is better than Leonard's, because it is a professional instrument. Stuart gets a postive review about his comic book store in a tweet from Neil Gaiman. As Penny gazes through the telescope, she sees something fuzzy streak through the sky; she photographs it, and Raj gets the impression that Penny saw a comet.
As Howard and Sheldon come to the comic book store, they find the place bustling with people. Sheldon doesn't take it too well, as he preferred it the way it was before. In Apartment 4A, Raj tells Leonard and Penny that they definitely saw a comet, much to Penny's delight. Raj points out that it was his telescope she was using. Leonard suggests that they share the credit, though Raj only put his name on the paper; after arguing about their discovery, an angered Penny tells Raj to leave.
Howard and Bernadette are prepared to go out for a date night. Unfortunately, Stuart can't make it to take care of Michael and Halley, because his store is so busy. Bernadette divides it up by her going out to dinner and Howard staying at home.