Super Mario Galaxy Edit
In Super Mario Galaxy, Mario is heading off to Princess Peach's Castle for the Star Festival when the party is crashed by Bowser in his airships. He lifts the castle into space and blasts Mario off into the unknown.
Mario wakes up on Gateway Galaxy and, with the help of the Star Bunnies, meets Rosalina and agrees to help her collect Power Stars and Grand Stars to power the Comet Observatory and have it go to Bowser's lair.
Super Mario Galaxy 2 Edit
On his way to another Star Festival, Mario discovers Bowser has grown to monstrous size and has kidnapped Peach. With the help of several Lumas, he travels to Starship Mario where he meets Lubba and customizes it to look like Mario.
Mario meets up with Yoshi near the beginning of his travels, and they pair up often to collect more Power Stars to run Starship Mario. All of his power-ups from the last game are used with the exception of the Ice Flower and Red Star. Mario also gains access to three new power-ups; the Cloud Flower, Rock Mushroom, and Spin Drill.