Galactic Centre was a point used to measure other planets and locations. It was used as a starting point for galactic coordinates. For example, Gallifrey was located at 10-0-11-0-0 by 0-2 from galactic zero centre (TV: Pyramids of Mars) while Miasimia Goria was located at 7-8-9-8-2-5-8-2-0-0 from galactic centre. (AUDIO: Planet of the Rani) The Galactic Centre was also the centre of power for human affairs during the time of Helen A's rule on Terra Alpha in the 24th century. (TV: The Happiness Patrol)