21900 Orus

21900 Orus is a Jupiter trojan asteroid from the Greek camp, approximately 53 kilometers in diameter, and a target of the Lucy mission to be visited in November 2028. It is among the 100 largest Jupiter trojans and has a rotation period of 13.5 hours. It was discovered on 9 November 1999, by Japanese amateur astronomer Takao Kobayashi at his private Ōizumi Observatory in Gunma Prefecture, Japan, and later named Orus after a slain Achaean warrior from the Iliad.