- "That ball of flame represents the power of the observatory. We call it the beacon. When you recover a Grand Star, a little Star Power will be restored, and the beacon will grow."
- ― Rosalina, Super Mario Galaxy
Beacon is an star placed in the center of the Comet Observatory in Super Mario Galaxy. It was used for all the Domes. When restoring a Grand Star, the color of the Beacon changes and grows; also the Dome lights up and it is now available to go inside.
When each star is put in first star, it lights up and turns orange, adding another Grand Star once, it turns yellow, then green, greenish-blue, blue and finally, turquoise, also it allows Mario to go in different Domes. When the beacon hits its last stage, Mario will be able to travel to the center of the universe to fight Bowser.
In Starship Mario's engine room, it appears to be a miniature beacon that runs on Power Stars. The miniature beacon is the energy source for the starship. It is only colored turquoise for the entire game.