1862 Apollo is a stony asteroid, approximately 1.5 kilometers in diameter, classified as a near-Earth object (NEO). It was discovered by German astronomer Karl Reinmuth at Heidelberg Observatory on 24 April 1932, but was lost and not recovered until 1973. It is the namesake and the first recognized member of the Apollo asteroids, a subgroup of NEOs which are Earth-crossers, that is, they cross the orbit of the Earth when viewed perpendicularly to the ecliptic plane (crossing an orbit is a more general term than actually intersecting it). In addition, since Apollo's orbit is highly eccentric, it crosses the orbits of Venus and Mars and is therefore called a Venus-crosser and Mars-crosser as well. Although Apollo was the first Apollo asteroid to be discovered, its official IAU-number (1862) is higher than that of some other Apollo asteroids such as 1566 Icarus, because it was a lost asteroid for more than 40 years and other bodies were numbered in the meantime. The analysis of its rotation provided observational evidence of the YORP effect. It is named after the Greek god Apollo, god of prophecy, music, healing and light, child of Zeus and Leto, after which the minor planets 5731 Zeus and 68 Leto are respectively named.
Satellite On 4 November 2005, it was announced that an asteroid moon, or satellite of Apollo, had been detected by radar observations from Arecibo Observatory, Puerto Rico, on 19 October – 2 November 2005. The announcement is contained in the International Astronomical Union Circular (IAUC) 8627. The satellite is only 80 m (260 ft) across and orbits Apollo just 3 km (1.9 mi) away from the asteroid itself. From the surface of Apollo, the satellite would have an angular diameter of about 2.0835 degrees.
Potentially hazardous object 1862 Apollo is a potentially hazardous asteroid (PHA) because its minimum orbit intersection distance (MOID) is less than 0.05 AU and its diameter is greater than 150 meters. Apollo's Earth MOID is 0.0257 AU (3,840,000 km; 2,390,000 mi). Its orbit is well-determined for the next several hundred years. On 17 May 2075 it will pass 0.0083 AU (1,240,000 km; 770,000 mi) from Venus.
See also Lost asteroid
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References
External links Lightcurve plot of 1862 Apollo, Palmer Divide Observatory, B. D. Warner (2005) Asteroids with Satellites, Robert Johnston, johnstonsarchive.net Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine) Dictionary of Minor Planet Names, Google books Asteroids and comets rotation curves, CdR Archived 29 July 2016 at the Wayback Machine – Observatoire de Genève, Raoul Behrend 1862 Apollo at NeoDyS-2, Near Earth Objects—Dynamic Site Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation 1862 Apollo at ESA–space situational awareness Ephemerides · Observations · Orbit · Physical properties · Summary 1862 Apollo at the JPL Small-Body Database