The centaurs are a class of icy planetoids named after the race of centaurs. Centaurs orbit the Sun between Jupiter and Neptune, crossing the orbits of the large gas giant planets. The first centaur to be discovered was 2060 Chiron in 1977, while the largest currently known is 10199 Chariklo discovered in 1997.
No centaur has yet been photographed up close by a spacecraft, although there is evidence that Saturn's moon Phoebe, imaged by the Cassini probe in 2004, may be a captured centaur. In addition, the Hubble Space Telescope has gleaned some information about the surface features of 8405 Asbolus.
Three centaurs, Chiron, 60558 Echeclus, and 166P/NEAT 2001 T4, have been found to display cometary comas. Chiron and 60558 Echeclus are now classified as both asteroids and comets. It is possible that other centaurs may also be comets, but as of March 2006 no cometary behavior has been discovered for any others.