Chiron, in Greek mythology, centaur, son of Kronos. He was a renowned sage, physician, and prophet. Among his pupils were Hercules, Achilles, Jason, and Asclepius. When Hercules accidentally wounded Chiron, the pain was so great that Chiron surrendered his immortality to Prometheus and died. Zeus then set him among the stars as the constellation Sagittarius.

Comet once thought to be the most distant known asteroid. Discovered in 1977, it travels in an unstable, eccentric orbit between those of Saturn and Uranus. In 1989 astronomers detected a fuzzy cloud (coma) around Chiron. Because such a cloud is a defining feature of comets, Chiron was reclassified as a comet. Seealso Centaur object.

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