Jobis was a gas giant famous for its beauty. Its atmosphere was home to a few animal species, including giant manta rays and crystal insects. Built in the skies were various platforms, including the hotel Platform Five and a research institute. These were, given the planet was protected under Galactic Heritage, built in such a way to protect the natural environment, with restrictions on the size of space ships allowed to enter the atmosphere.
Jobis was once visited by the First Doctor, Vicki Pallister, Ian Chesterton, and Barbara Wright. They stayed on Platform Five for several weeks, although the Doctor eventually left to visit the research platform. During their visit, the planet was attacked by the Rocket Men, who captured the Doctor's companions among other hostages. The Doctor, meanwhile, was able to hold out against them by protecting the scientific platform with a force field. He, along with the other scientists, communicated with the giant manta rays and convinced them to help defeat the Rocket Men. Their leader Ashman was among the casualties. (AUDIO: The Rocket Men)