- “The Trial Galaxies merely reflect your own abilities. You may find great joy...or great disappointment. You may try three types of trials. If you truly are the one who can save the universe, you will pass them all.”
- —Green Luma, Super Mario Galaxy
If the player recovers three special Green Stars, three Green Lumas will appear on the Comet Observatory, which will then activate a green Launch Star located near the Garage. By using it, Mario or Luigi is able to access the Planet of Trials, a small planet orbiting the Comet Observatory. There, three more Green Lumas will each transform into an additional green Launch Star when talked to. These Launch Stars will take Mario or Luigi to the three Trial Galaxies. Once the player has collected all 120 Power Stars in the game with both Mario and Luigi, a fourth Green Luma will appear on the reverse side of the Planet of Trials. This Green Luma will allow the player to go to the Grand Finale Galaxy when Mario or Luigi talks to it.
Names in other languages
|French||Galaxie des épreuves||Trials Galaxy|
|Italian||Galassie Sfide||Challenge Galaxies|
|Spanish||Galaxias Reto||Challenge Galaxies|
- In Super Mario Galaxy 2, the Rolling Coaster Galaxy and Fleet Glide Galaxy have similar purposes as the Trial Galaxies, as they are harder versions of previously-appeared galaxies that have a minigame as its main mechanic.
|Missions and galaxies in Super Mario Galaxy|
|Area||Main galaxies||Boss galaxies||Hungry Luma galaxies|
|Planet of Trials||—||—|
|Center of the universe||—||—|
|* Mission only available when a Prankster Comet is in orbit.|