If Springfield's residents can relate to science at all, it is at the level of relating to a cartoon character or baseball game. For this reason my colleagues would say it has a post-modern sensibility, but I wouldn't go there myself, because that is precisely to adopt the kind of wannabe authoritative stance that the show parodies. As punishment for mocking his school's science week, Bart has to help in an exacting and laborious comet search. When the school principal is momentarily distracted, Bart malevolently spins the telescope like a roulette wheel, spots a comet and calls the observatory, which names it the Bart Simpson Comet. However, the comet is heading directly for Springfield.
Scientists build a rocket to intercept the comet and blow it up.
As you've guessed, the rocket misses and instead blows up the only bridge out of town. Most of Springfield's inhabitants squeeze into a bomb shelter, but leave at the last minute so that they can all die together. This, too, fails because the comet disintegrates in the atmospheric pollution hanging over the town. The one fragment of the comet to make it through hits the bomb shelter where they had huddled for safety moments before. When we grab one choice, and find that it inevitably founders, new possibilities emerge and we are spared the worst.