The Gaea Trilogy consists of three science fiction novels by John Varley. The stories tell of humanity's encounter with a living being in the shape of a 1,300 km diameter Stanford torus, inhabited by many different species, most notably the centaur-like Titanides, in orbit around the planet Saturn. The novels are: Titan (1979) Nebula Award nominee, 1979; Hugo Award nominee, Locus Award winner, 1980 Wizard (1980) Hugo and Locus Award nominees, 1981 Demon (1984) Locus Award nominee, 1985 Source: Wikipedia (en)