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