The Boo Moon Galaxy is a galaxy in the game Super Mario Galaxy 2 located in World 5. It takes place in a haunted setting, and features the poison swamp substance which Mario will die if he falls into, as well as Snake Blocks.
Silver Stars Pop-Up
Mario has to make his way through the boo maze, traverse through a poison swamp by using snake blocks, then blast off to the moon and then go to a Pop-up Book to find Silver Stars to recover the Power Star.
Haunting the Howling Tower
The Star in the Sinking Swamp
These only appear in Mission 1: Silver Stars Pop-Up.
Green Star 1
In the Sinking Swamp, take the secret path and perform a Long Jump to the star.
Green Star 2
Jump off the Moon's left side and perform a Spin Jump to get the star.
Green Star 3
Perform a Long Jump off the Pop-Up Planet.
True to the Boo Moon's name, its planets have a haunted theme.
Starting Planet (Boo Maze)
This ball is a small ball and the only place that appears to have Standard Gravity. It is visited in every mission. It is about 40 metres in diametre. When Mario has landed here, he will have a "lantern". Mario has to use this lantern to navigate his way through the maze and reach the Launch Star at the end. Boos infest the planet.
Sinking Swamp Planet
This flat planet is a swamp whose surface at first appears to be flat, but it eventually folds up. It is named as such in the Secret Star mission. Mario has to use the Snake blocks in order to make his way to the next area. The snakes do not return to their starting point, so if Mario will die if the snakes leave him.
While it isn't the real thing, a crescent moon appears as a planet in this galaxy. Standing on its sides will cause it to tilt to Mario's weight, and standing on one side will cause him to fall into deep space and die of the lack of oxygen. In Mission 1, Mario has to collect five Star Chips to form a Launch Star, which appears on the planet's right side. Mario later returns here during his trip home after Bowser is defeated.
This graveyard-themed planet folds up like a book. It is about 80 metres on a side, bigger than the Starting Planet. To activate the planet's folding mechanism, Mario must use his Ground Pound attack to hit a pink switch at the South. Five Silver Stars are scattered here.
This planet earned its name from the fact that it is a tower infested with winds. The Howling Tower is visited only in Mission 2, where it is the mission's namesake and "end zone".
- The galaxy's background appears to be reused from Super Mario Galaxy's Ghostly Galaxy, Bonefin Galaxy, and Boo's Boneyard Galaxy.
- "Boo Moon" is a pun on "Blue Moon" and Boo.