Planet (Listen)

A barren, uninhabited planet was thought to be the very last planet left at the end of the universe.

Astronomical data
The planet's surface was rocky and desolate with a spiked, reddish, mountainous terrain and a pink and scarlet sky, dwarfed by an enormous, expanding star. The planet's atmosphere was oxygen rich and apparently breathable for humans, according to the Twelfth Doctor. (TV: Listen)

History
It was believed to be the last planet in existence at the close of the universe as every other planet had been destroyed by heat death. Time travel pioneer Orson Pink's time shuttle crash landed there following an experimental time shot from the 22nd century. Pink was reluctant to leave the capsule and venture onto the planet's surface, fearful of an unknown entity he believed existed beyond the airlock.

The Twelfth Doctor and Clara Oswald landed on the planet towards the end of its life, just before it was destroyed by heat death, searching for a mysterious and perfectly-camouflaged creature, eventually rescuing Orson from his isolation in the process, and leaving the world and the universe supposedly uninhabited. (TV: Listen)

Behind the scenes

 * AUDIO: R&J implies that Jack Harkness and River Song were causing the noise heard on the planet, with Jack also referencing a woman waiting to play a game of chess, implying this world to be Gallifrey.