3. The Fountains of Enceladus

Saturn's mysterious moon Enceladus has startled astronomers with its amazing ice geysers, which spew out material into space. Sir Patrick Moore talks to the scientists who are trying to unlock the secrets of this tiny world. Dr Chris Lintott visits the Open University to find out the latest on our own Moon. He meets scientists from the Japanese Kaguya mission and the Indian Chandrayaan mission, with its British instrument CIXS.