Junk was an interplanetary scrap yard found in the Andromeda Galaxy. Old and discarded technology was dropped off here to be sold, crushed and hurled into the sun. It was divided into colour-coded provinces and each province was divided into lettered sections; each section was looked after by a manager and a team of robots.
The Tenth Doctor and Donna Noble visited greeny-yellow province (sector J) and met general manager 77141 and the robots Chuck and Crusher during their trip to the Andromeda Galaxy. (PROSE: Shining Darkness)