It was used by the pirate Captain Nathaniel Flint to hide his treasure. Dr. Delbert Doppler soon set out on a mission to find Treasure Planet by hiring the pirate John Silver and his crew, under the command of Captain Amelia. All of Silver's crew members wanted the treasure that Flint hide in the center of the planet.
In truth, however, Treasure Planet was never really a planet at all. Rather, it was a vast spheroid-shaped mechanism created by an ancient alien race, composed of incredibly advanced technology. A spherical map inputted into the right slot opens up a portal to anywhere in the universe. Flint somehow commandeered Treasure Planet's technology to go across the universe stealing treasure.
To make sure no one could steal Flint's treasure, the entire planet was rigged to explode which led to its demise after Sliver and his crew triggered a booby trap. Silver and his pirates triggered this booby trap and were forced to flee the planet on the RLS Legacy. However, flying debris damaged the ship's motive power and it couldn't escape so Jim Hawkins used the planet's portal to get them to safety after changing the destination. Moments after the ship fled to safety through the portal, Treasure Planet exploded behind them.
Treasure Planet resembles the planet Saturn because of it's rings which glow a bright green color. The surface of the planet is very jungle-like at first glance. Closer inspection however reveals that much, if not all of its surface is in fact mechanical.