Vulcan (Invasion of the Daleks)

Vulcan was the first planet out from Sol on the Daleks' chart of the solar system as they planned to invade in 2400. (COMIC: Invasion of the Daleks) However, others believed that Mercury was the first planet, (AUDIO: The Satanic Mill) making Earth "Sol III". (TV: Voyage of the Damned)

Vulcan appeared as an exhibit in the Museum of Things That Don't Exist. (PROSE: The Taking of Planet 5)

Behind the scenes

 * Scientists of the 19th and 20th centuries hypothesised the existence of a planet between the orbit of Mercury and Sol, and sometimes referred to that planet as Vulcan. This theory has since been discredited. The Vulcan in The Taking of Planet 5 is a reference to this.