There are a total of 120 Power Stars to find in Super Mario Galaxy. You’ll find most of them by just completing each of the game’s levels, but there are also 51 hidden stars to collect throughout.
In this Super Mario Galaxy guide, we’ll tell you the location of the 3 Green Stars and list the Trial Galaxy Power Stars they allow you to reach.
Green Star locations
There are three Green Stars that you need to collect in order to open the Trial Galaxies.
Fountain Dome // Battlerock Galaxy
Breaking into the Battlerock – Luigi under the Saucer
Once you (spoiler) rescue Luigi during Kitchen Dome // Ghostly Galaxy // Luigi and the Haunted Mansion, he’ll head off on his own to find some Power Stars. He, being Luigi, gets stuck every time he wanders off. He’ll mail you a photo, and you’ll have to go off to find him. The first place he’ll go is in the Good Egg Galaxy — but he will only give you a regular Power Star there. For the Green Star he finds, you’ll have to go to Battlerock.
All the way at the end of this level, you would normally kite a Bullet Bill to a dome containing the Power Star. To find Luigi, you’ll need to kite a Bullet Bill around to the underside of the saucer.
Once Luigi is rescued, he’ll give you a Green Power Star (more on these below).
Kitchen Dome // Buoy Base Galaxy
The Floating Fortress – The Secret of Buoy Base
To get this hidden star, you’ll need play a lot with Torpedoes Ted and Bullets Bill. Dive under the water at the start, and look for a pipe covered by a dome. Lead a torpedo to it to reveal a pipe. Through the pipe, you’ll end up on the outside of the planet.
Dodge the Bills as you cross the path there. You’ll have to very carefully lead a Bill through the various obstacles to the dome protecting this Green Star.
Bedroom Dome // Dusty Dune Galaxy
Blasting through the Sand – Treasure of the Pyramid
Start the level normally, and make your way through the Pokeys (Pokies?). When you reach the platforms near the ring of rolling boulders, jump to the center platform with the Sling Star. Don’t take the star, though. Instead, run around to the underside to pick up a Rainbow Star. Use your invincibility to smash the boulders and pick up some Star Bits.
Head back to the first platform you landed on, and run to the bottom side. There’s a Hungry Luma here who needs 20 Star Bits.
You’ll head inside a pyramid-like planet. Here, you’ll have to run up and down the inside of the planet to collect five silver stars. Once you’ve got them all, you’ll get the Green Star.
Once you’re collected all three Green Stars, there will be a new, green Launch Star in the Observatory. That will send you to a three-lobed planet where you can tackle the three Trial Galaxies. These are challenging levels using mechanics you’ve encountered elsewhere in the game.
The three Trail Galaxies are:
- Rolling Gizmo Galaxy
- Loopdeeswoop Galaxy
- Bubble Blast Galaxy