Skardal, also spelt Skardel was a rogue planet.
A collision with Omega Three altered its course to one which would cause it to collide with Skaro. The Daleks altered its course to one away from Skaro and which would cause it to collide with Mechanus. (TV21: The Rogue Planet) Skardal was destroyed by a Dalek warhead stolen by 2K and anti-missile rockets fired by the Daleks, thus preventing the destruction of Mechanus. (TV21: Impasse)
Behind the scenes
- Skardal was spelled Skardel in Impasse.