Cotter Paluni's World

Cotter Paluni's World was a planet mentioned by the Tenth Doctor as somewhere he wanted to take his companion Donna Noble when he mistakenly thought she was leaving him to stay on Earth. The planet was said to have "lightning skies". (DW: The Sontaran Stratagem)

It was a planet entirely cut off from the universe. Any ship entering the planet's atmosphere was shot down by the red lightning. (TWA: Red Skies)