When Luigi first enters the Observatory, the first thing he founds is a small telescope. Luigi can then walk towards it and get a better look. When he sees through, he notices a small moon; at which point the Meteor Ghosts will appear. Luigi is able to suck a Meteor Ghost into the slot of his Poltergust 3000, and then fire it at the moon, causing the it to explode, and revealing right after a path to Mario's Star.
- Luigi does not lose any HP if he gets hit by a Meteor Ghost, making it one of two types of ghosts in-game which cannot deal damage at all (the other one are Ceiling Surprises).