A three-dimensional model of 1862 Apollo based on its light-curve
|Discovered by||K. Reinmuth|
|Discovery site||Heidelberg Obs.|
|Discovery date||24 April 1932|
|NEO · PHA
|Orbital characteristics |
|Epoch 16 October 2009 (JD 2455120.5)|
|Uncertainty parameter 0|
|Observation arc||84.25 yr (30,774 days)|
|1.78 yr (651 days)|
|Earth MOID||0.0257 AU|
|Q (Tholen, SMASS)
B–V = 0.819
U–B = 0.481
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 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-crosser, that is they cross the orbit of Earth when view perpendicular to the ecliptic plane (crossing an orbit is a more general term that 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, due to the fact that is 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.
On November 4, 2005, it was announced that an asteroid moon, or satellite of Apollo, had been detected by radar observations from Arecibo Observatory, Puerto Rico, October 29 – November 2, 2005. The standard provisional designation for this satellite is S/2005 (1862) 1. The announcement is contained in the International Astronomical Union Circular (IAUC) 8627 . The satellite is just 80 m across and orbits Apollo closely, in an orbit a mere 3 km in radius .
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. The Earth MOID is 0.0257 AU (3,840,000 km; 2,390,000 mi). The 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.
- Durech, J.; Vokrouhlický, D.; Kaasalainen, M.; Weissman, P.; Lowry, S. C.; Beshore, E.; Higgins, D.; Krugly, Y. N.; et al. (September 2008). "New photometric observations of asteroids (1862) Apollo and (25143) Itokawa – an analysis of YORP effect" (PDF). Astronomy and Astrophysics 488 (1): 345–350. Bibcode:2008A&A...488..345D. doi:10.1051/0004-6361:200809663.
- "JPL Small-Body Database Browser: 1862 Apollo (1932 HA)" (2015-03-16 last obs.). Jet Propulsion Laboratory. Retrieved September 2015.
- Gehrels, Tom (1994). Hazards Due to Comets and Asteroids. Tucson: University of Arizona Press. pp. 540–543. ISBN 0816515050.
- Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names – (1862) Apollo. Springer Berlin Heidelberg. p. 149. ISBN 978-3-540-29925-7. Retrieved November 2015.