The Comet Observatory is one of the many locations in LEGO Dimensions 2: The Rise of Enoch, from the Super Mario franchise.
The Comet Observatory is the home to Rosalina and the Lumas. It plays the role of a "hub" area in Super Mario Galaxy, the only game in which it is accessible so far. From this location, Mario is able to access the many galaxies in the game via a number of domes, of which only one is initially open. Others are opened as progress is made through the game and Grand Stars are returned to the Comet Observatory. As each Grand Star is collected, they charge the sun-like sphere of energy in the middle of the observatory, also known as the beacon, lighting up a new section of the hub.
The observatories in the Comet Observatory are the Terrace, Fountain, Kitchen, Bedroom, Engine Room and Garden. Situated between the Engine Room and the Garden is the Gate, which allows access to the Gateway Galaxy, which was the first galaxy featured in the game.