Rosalina

Princess Rosalina (known as Rosetta in Japan, and Estela in Spain) is a princess who appears in Super Mario Galaxy. She first appears in the Gateway Galaxy. She wears a blue dress and looks oddly similar to Princess Peach. She's the mother of the Luma. She teaches Mario how to do a Star Spin and tells him to find Peach. She is also shown to give Mario a Luma named Tyke. Princess Rosalina also has a castle. Her duty is watch over and protect the Cosmos as well as the Lumas.

Rosalina's Story
Rosalina's backstory is chronicled in a storybook told by her in the Comet Observatory's Library. 9 chapters are unlocked throughout the game, the last of which unlocked by winning the last Bowser battle and ending the game.

The story begins with Rosalina finding a rusty spaceship (resembling the Starshroom) with a Star Child inside. The Luma introduced itself, revealing it was wating for its Mama. Rosalina bonded with the Luma and promised that she would wait with it. Armed with her father's telescope, Rosalina stargazed for years, searching for the comet that carried the Luma's mother. Fearing it was taking too long, Rosalina and Luma fixed and boarded the spaceship and set off into space.

Traversing through asteroids, Rosalina grew very hungry. She had brought essentials for the trip. The telescope, food, her stuffed bunny (resembling a Space Rabbit, and tea, but forgetting water. At the sight of a pouting Rosalina, Luma then told her that Star Bits would be all she needed, and began to share them.  Leaning out the spaceship the two collected Star Bits to eat.

One night a shimmering Comet made of ice flew past the ship. Hoping Luma's mama would be there, the two set foot onto it. Mama was nowhere to be found, but star bits clustered to the south. One night in a dream, Rosalina remembered her Mother. Rosalina's mother greatly resembled how she herself would come to look. In the dream Rosalina's mother was going away. Rosalina's mother told her not to worry, because she would always be watching her. Clinging to her mother, she cried. Upon awaking Luma noticed tears coming from Rosalina's eyes (and mistaking them for Star Bits). However, Rosalina explained what they were upon waking. She was crying them because she would never see her mother again. At this, they both broke down in tears over their lost mothers.

Continuing the search, Rosalina comforted Luma. She told Luma she would take of it, and with that a spark in her heart went off. She became determined to mother the Luma and then started to make the home out of the comet. With tools found inside the comet Rosalina built what would become Domes housing the Galaxies for Mario. For now however, it was a shelter for Luma. Once completed it seemed very large for her and just one Luma.

One day a comet flew close, and another Luma came out of it. It was silent once the Lumas met, until one affectionately called out and said Rosalina was it's Mama. "My Mama, My Mama!" the Lumas fought over her love. Rosalina found this so touching she couldn't help but laugh. Out of the comet many more Luma came, and all of them called her Mama and fought over her. She took them all under her wing, and named all of them, moving them all into her newly built house on the comet.

One night Rosalina remembered her home planet, and wondered if everything was alright there. She looked through the telescope until she could make out its surface, even seeing grass and a tree. She saw her favorite spot for stargazing, and it reminded her of her family. She wanted to go home, but she knew she'd never see her mother again. At this time it's revealed her mother had died, and was burried under the tree in view.

The Luma comforted a crying Rosalina, assuring her that she shouldn't be sad and that her mother is a part of her and will always be close by. It was at this time the Luma she met inside the ship had an idea. The Luma transformed the comet into the Comet Observatory to help in finding all their Mamas. The Lumas all explained that when they grow up, they transform into various things. Rosalina was so overcome with emotion due to this selfless act she thanked all the lumas that had huddled around to hug her. From that day on Rosalina never cried again.

The observatory grew and grew into a better home, and Rosalina and the Lumas were proud to call it their home. At a welcoming party for a new Luma, Rosalina and the others baked a cake topped off with Star Bits. Coming together in such a way made her realise they were her new family, and she was determined to raise them and send them off to all their destinies. It's at this time she came to call herself the mother of the Lumas.

Rosalina was reminded yet again of her home one night. Even though she had a new goal in her life, she thought it'd be nice to visit her favorite spot from her past. So every 100 years the Comet Observatory passes over the Mushroom Kingdom so that she can re-visit.

Princess Rosalina has many powers. For example, once sufficient power is restored to the Comet Observatory, she is able to use her powers to surround it in a force field, transforming it into a starship as a form of transportation. Also, if you attempt to jump on her, she will be protected by a force field.

Princess Rosalina is voiced by the veteran voice actress Mercedes Rose.

Trivia

 * Princess Rosalina's similarity in appearance to Peach is no coincidence. In preplanning of Super Mario Galaxy, Princess Rosalina was planned to be related to her.
 * Princess Rosalina is similar in appearance to Glinda from the Wizard of Oz. After Mario first meets her, she dissapears in a bubble that floats up fades away in a similar manner as Glinda uses in the film.