Raxus Prime was used as a galactic junkyard for thousands of years. Because of this, a large portion of the planets mass was actually alien metals. Old machinery, especially starships often found their way to the planet. Because of this, the planet is a haven for scavengers looking for spare parts or free equipment.
In the year 3 BBY, Darth Vader sent his apprentice Starkiller to Raxus Prime in order to assassinate Kazdan Paratus. Paratus was a jedi who survived Order 66 and sought refuge on the planet. Being on a planet that was scarce of life, he was drove to madness and constructed a makeshift Jedi Temple with robotic equals of previous members. In a duel with Starkiller, Paratus was killed after a fierce battle.