Long ago, before anything had ever happened, there was a meteor, a special meteor at that. After sailing along our blank galaxy, it eventually found our sun, our biggest star. The meteor crashed into it but it didn't explode. For some strange reason, the flaming ball had survived but, it had special powers now.
Now, it could regenerate after hitting the ground, heck, the ground didn't even combust once the ball hit it. Also, whoever touched it would gain special powers.
Millions of years later, after we were created and the galaxy had more things then an "always burning star", the meteor landed in the Mushroom Kingdom. Puzzled at the sphere not destroying them all, the residents (Toads) asked the guards to take it to the princess A.K.A Peach. But you knew that already.
To their surprise, the guards didn't find the meteor heavy at all. Once they got to the castle, the guards knocked on the door only to find out that they had knocked "down" the door. Luckily, no one was at the entrance at the time. The guards went down the hall into the throne room where Peach was sitting there quietly, listening to one of the Mario Bros. stories.
Peach had said to lock away the ball and that's what they did. A few years after that, evil tried to take this powerful meteor. Now, Peach was getting concerned. If they didn't do something now, the residents of this fair kingdom would probably perish because of all the attacks these bad people were doing.
Luckily, the mother of all Lumas', Rosalina, had noticed this and put a shield around the once flaming ball. The shield would break for those who were good. After that, the meteor rose out of its safe and flew back into space. And to this day, on June 1'st, the meteor would come back to Earth and give good people that power. Since that is today, how about we have a look of the Mushroom Kingdom, shall we?