Cressida (moon)

Cressida was a moon of Uranus. It was turned into a space station in the 41st century. One of its main functions was to adjust the transmissions going through the Hub, which was the Galactic Federation's communications system. In 4010 the asteroid Maleficent collided with Uranus. The chemical reaction between the rare ores in the asteroid and the planet's atmosphere resulted in an amazing display. Merculite tried to avert the collision, but was stopped by the Seventh Doctor. However, in the process Cressida was destroyed. (PROSE: Uranus)