2456 Palamedes /pæləˈmiːdiːz/ is a large Jupiter trojan from the Greek camp, approximately 90 kilometers (56 miles) in diameter. It was discovered on 30 January 1966, by astronomers at the Purple Mountain Observatory in Nanking, China.^[1] The assumed C-type asteroid has a rotation period of 7.24 hours and belongs to the 50 largest Jupiter trojans.^[5] It was named after Palamedes from Greek mythology.^[3]

Palamedes is a dark Jovian asteroid orbiting in the leading Greek camp at Jupiter's L₄ Lagrangian point, 60° ahead of the Gas Giant's orbit in a 1:1 resonance (see Trojans in astronomy).^[6] It is also a non-family asteroid in the Jovian background population.^[7][12]

It orbits the Sun at a distance of 4.7–5.5 AU once every 11 years and 7 months (4,244 days; semi-major axis of 5.13 AU). Its orbit has an eccentricity of 0.07 and an inclination of 14° with respect to the ecliptic.^[4] The body's observation arc begins with a precovery taken at Palomar Observatory in February 1953, nearly 13 years prior to its official discovery observation at Nanking.^[1]

This minor planet was named from Greek mythology after Palamedes, the most intelligent of all the Greek commanders of the Trojan War.^[3] The official naming citation was published by the Minor Planet Center on 28 January 1983 (M.P.C. 7618).^[13]

Palamedes is an assumed carbonaceous C-type asteroid.^[5] It has an average V–I color index of 0.920±0.024, typically associated with D-type asteroid (also see table below).^[5]