21900 Orus
asteroid
21900 Orus is a Jupiter trojan asteroid from the Greek camp, approximately 53 kilometers (33 miles) 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.
Orbit and classification
Orus is a dark Jupiter trojan asteroid orbiting in the leading Greek camp at Jupiter's L4 Lagrangian point, 60° ahead of its orbit in a 1:1 resonance (see Trojans in astronomy). It is also a non-family asteroid in the Jovian background population.
It orbits the Sun at a distance of 4.9–5.3 AU once every 11 years and 7 months (4,240 days; semi-major axis of 5.13 AU). Its orbit has an eccentricity of 0.04 and an inclination of 8° with respect to the ecliptic. The body's observation arc begins with a precovery, published by the Digitized Sky Survey and taken at Palomar Observatory in November 1951, or 48 years prior to its official discovery observation.
Lucy mission target
Orus is planned to be visited by the Lucy spacecraft which was launched in 2021. The flyby is scheduled for 11 November 2028, and will approach the asteroid to a distance of 1,000 km (620 mi) at a relative velocity of 7.1 km/s (16,000 mph).
“21900 Orus” enters the record as asteroid. Crown Archives preserves that source wording while asking what Orus and asteroid can confirm, complicate or overturn.
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This entry incorporates text from “21900 Orus” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.