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Orbis was a water world with salinity significantly higher than that of Earth's oceans. Its seas were dense and buoyancy was little problem. The planet had seasonal storms, which were increased due to an approaching stellar manipulator (AUDIO: Orbis)
Orbis was inhabited by the Keltan race. However their settlements on Orbis were, over the course of six hundred years, frequently destroyed by the presence in close orbit of a remote stellar manipulator that took on the appearance of a moon. The Eighth Doctor remained on the planet during this long passing of six centuries, stranded for so long that his memories began to crumble. (AUDIO: Orbis)