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. The satellite is only across and orbits Apollo just 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 .
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External links
- , Palmer Divide Observatory, B. D. Warner (2005)
- Asteroids with Satellites, Robert Johnston, johnstonsarchive.net
- Asteroid Lightcurve Database (LCDB), query form (info )
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
