1862 Apollo

1862 Apollo /əˈpɒloʊ/ 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.

DiscoveredbyK. Reinmuth

DiscoverysiteHeidelberg Obs.

Discoverydate24 April 1932

MPCdesignation

(1862) Apollo

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1862 Apollo

A three-dimensional model of 1862 Apollo based on its light-curve
Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	24 April 1932
Designations
MPC designation	(1862) Apollo
Pronunciation	/əˈpɒloʊ/[2]
Named after	Apollo (Greek mythology)
Alternative designations	1932 HA 24px (astrological)
Minor planet category	NEO Â· PHA Venus-crosser Mars-crosser Apollo asteroids
Orbital characteristics[1]
Epoch 21 November 2025 (JD 2461000.5)
Uncertainty parameter 0
Observation arc	95.27 yr (34796 days)
Earliest precovery date	24 April 1932
Aphelion	2.2945 AU (343.25 Gm)
Perihelion	0.64733 AU (96.839 Gm)
Semi-major axis	1.4709 AU (220.04 Gm)
Eccentricity	0.55992
Orbital period (sidereal)	1.7840 yr (651.60 d)
Mean anomaly	113.88°
Mean motion	0° 33m 8.928s / day
Inclination	6.3514°
Longitude of ascending node	35.542°
Argument of perihelion	286.05°
Earth MOID	0.0260113 AU (3.89124 Gm)
Jupiter MOID	3.05801 AU (457.472 Gm)
TJupiter	4.413
Physical characteristics
Dimensions	1.5 km (0.93 mi)[3]
Mean radius	0.75 km
Synodic rotation period	3.065 h (0.1277 d)
Geometric albedo	0.25[1]
Surface temp. min mean max Kelvin[4] 171 K 214 K 322 K Celsius −102 °C −59 °C 49 °C Fahrenheit −151.6 °F −74.2 °F 120.2 °F
Spectral type	Q (Tholen, SMASS) B–V = 0.819 U–B = 0.481
Absolute magnitude (H)	16.09[1]

Close

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.^[5]

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 named.^[6]