The Dead planet was Earth after it was destroyed by the expanding Sun
After The Doctor and Rose Tyler visited the space station celebrating the planet Earth after the Humans and Animals left to find a new home out Among the Stars. The Sun expanded, leading up to that The Doctor and Rose Tyler had to thwart Lady Kassandra's plans to murder everyone on the station using the heat of the expanding Sun. Year's later The Matrix of Gallifrey arrived in the year 60,345,Acorn/Apple,051 and began using the last of Time Lord technology to start a new planet.