Chiron discovered 1977

Chiron, an asteroid/minor planet/comet/centaur/whatsit, was discovered by Charles Kowal November 1, 1977 from images taken October 18 from the Palomar Observatory in southern California.  It may have been observed as far back as 1895.

At first, Chiron (named after the wisest and justest centaur from Greek mythology) was classified as a minor planet because its orbit lay between Saturn and Uranus, much further than the asteroid belt.  Subsequently, its classification was downgraded to an asteroid. 

Then in 1988, it brightened by 75% which is characteristic of comets, but not asteroids.  In 1993, a tail was discovered so NASA thought it was a comet.  So they decided, why not classify it as both a comet and a minor planet.  Chiron is officially known as a centaur, a dual classification of comet and minor planet, orbiting between the asteroid belt and the Kuiper belt.




https://en.wikipedia.org/wiki/2060_Chiron