Kent Brockman's list of gay people is composed of the show's production staff, who had to sign legal agreements that they would not sue their own show. As a result, according to Matt Groening, many of the staff appear on lists of gay people on the Internet.
Principal Skinner tells Bart that he missed the chance to name a discovery after himself once, but that he got back at Principal Kohoutek. This may be in reference to an actual comet discovered by a Czech astronomer named Kohoutek in 1973. It is known officially as Comet Kohoutek. Like Bart's comet, Comet Kohoutek was considered to be a disappointment.
David Mirkin considers the episode to be one of his all time favorites, calling it a "perfect Simpsons episode" due to the size of the plot, emotion and observational humor.
After seeing an issue of Time magazine, which presented the threat of comets hitting Earth on its cover, the writing staff decided to have an episode based on the concept of a comet hitting Springfield. They fleshed out the episode's plot over several days and John Swartzwelder then set about writing the details of the script.
The episode marks the first appearance of Database, a character Matt Groening dislikes if he is used for anything more than one line.