Cobalt Star

The Cobalt Star is the name given to the power source for Professor E. Gadd's time machine. The Cobalt Star was unfortunately shattered into the Cobalt Shards, forcing the Mario Bros. to go on an extensive journey to retrieve them, not knowing that doing so would free the elder Princess Shroob and restore her power to her. It seems that Baby Luigi was the only one knowing because he cried at the Cobalt Star.