Castor 36

Castor 36 was a planet far out beyond Alpha Geminorium. The Sontarans promised genius Luke Rattigan to take him and the students at Rattigan Academy to the planet. Luke's ideas for the planet's new name included Rattigan's World and Earth Point Two. However, the Sontaran leader, General Staal, later admitted that Castor 36 was a lie designed to trick Rattigan and his students (DW: The Poison Sky).