chiron

Chiron is a figure in Greek mythology—a centaur renowned for wisdom, healing, and teaching. He is described as a son of Cronus and the sea-nymph Philyra, and as the most civilised of the centaurs, noted for knowledge rather than wild revelry. Chiron tutored many legendary heroes, including Achilles, Asclepius, and Jason, and was esteemed for skill in medicine, music, and prophecy. Unlike other centaurs, he is portrayed as gentle and scholarly. In many traditions he is wounded by an arrow dipped in the venom of the Hydra; because he is immortal, the wound torments him until, in some accounts, he relinquishes his immortality to Prometheus in order to die. Zeus places Chiron among the stars as a constellation.

In astronomy, Chiron is the first identified centaur—a class of small icy bodies with orbits that lie between those of the giant planets. It was discovered on November 1, 1977, by Charles T. Kowal and named after the mythological figure. Chiron displays both asteroid-like and cometary characteristics, including episodes of activity and a tenuous coma. It orbits the Sun on a highly elongated path that crosses the orbits of outer planets, with a period of many years. Diameter estimates place it around two hundred kilometers, making it one of the larger known centaurs. The discovery of Chiron helped define the centaur category and has informed studies of the evolution and behavior of icy bodies in the outer Solar System.