1862 Apollo

1862 Apollo

Discovery
Discovered by	Karl Reinmuth
Discovery date	April 24, 1932
Designations
Named after	Apollo
Alternate name(s)	1932 HA
Minor planet category	Apollo Venus-crosser asteroid, Mars-crosser asteroid
Orbital characteristics
Epoch November 26, 2005 (JD 2453700.5)
Aphelion	343.216 Gm (2.294 AU)
Perihelion	96.850 Gm (0.647 AU)
Semi-major axis	220.033 Gm (1.471 AU)
Eccentricity	0.560
Orbital period	651.543 d (1.78 a)
Average orbital speed	22.50 km/s
Mean anomaly	38.337°
Inclination	6.355°
Longitude of ascending node	35.777°
Argument of perihelion	285.784°
Proper orbital elements
Physical characteristics
Dimensions	1.7 km
Mass	5.1×1012? kg
Mean density	2.0? g/cm³
Equatorial surface gravity	0.0005? m/s²
Escape velocity	0.0009? km/s
Rotation period	0.1277265 d (3.065436 h)
Albedo	0.21 [1]
Temperature	~222 K
Spectral type	Q
Absolute magnitude (H)	16.25

1862 Apollo ( /əˈpɒloʊ/) is a Q-type asteroid, discovered by Karl Reinmuth in 1932, but lost and not recovered until 1973. It is named after the Greek god Apollo.

It is the namesake of the Apollo asteroids, and the first one discovered, although because it was lost for a time its asteroid number (1862) is higher than that of some other Apollo asteroids such as 1566 Icarus. Analysis of the spin of this object provided observational evidence of the YORP effect.

It was the first asteroid recognized to cross Earth's orbit. It is also a Venus- and Mars-crosser asteroid.

Moon

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 [2]. The satellite is just 80 m across and orbits Apollo closely, in an orbit a mere 3 km in radius [3].

Further reading

• 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". Astronomy and Astrophysics 488 (1): 345–350. Bibcode 2008A&A...488..345D. doi:10.1051/0004-6361:200809663. http://www.rni.helsinki.fi/~mjk/YorpApoIto.pdf. 

See also

• Lost asteroid

External links

• (1862) Apollo in the Minor Planet Center's Database
• NASA JPL orbital simulation 1862 Apollo (Java)