World 5 (Super Mario Galaxy 2)

World 5: Trial of the Galaxies is the fifth world featured in Super Mario Galaxy 2. It is located in a galaxy cluster. It holds seven galaxies, the last of which, Bowser Jr.'s Boom Bunker, features the third and last encounter with Bowser Jr., who attacks with his Boomsday Machine.

Galaxies

 * Space Storm Galaxy
 * Slipsand Galaxy
 * Shiverburn Galaxy
 * Boo Moon Galaxy
 * Upside Dizzy Galaxy
 * Fleet Glide Galaxy
 * Bowser Jr.'s Boom Bunker