1221 Amor

1221 Amor

Orbit of 1221 Amor on 1932-03-12: yellow - Sun, green - Earth, red - Mars, light blue - Amor, dark blue - Jupiter
Discovery
Discovered by	Eugène Joseph Delporte
Discovery site	Uccle
Discovery date	March 12, 1932
Designations
Alternative names	1932 EA1
Minor planet category	Amor II asteroid, Mars-crosser asteroid
Orbital characteristics
Epoch June 27, 2015
Aphelion	2.755 AU (412.1 Gm)
Perihelion	1.084 AU (162.2 Gm)
Semi-major axis	1.919 AU (287.1 Gm)
Eccentricity	0.435
Orbital period	2.66 yr (971.315 days)
Average orbital speed	20.44 km/s
Mean anomaly	91.374°
Inclination	11.879°
Longitude of ascending node	171.346°
Argument of perihelion	26.634°
Proper orbital elements
Proper eccentricity	0.439
Proper inclination	11.096°
Proper mean motion	135.281 deg / yr
Proper orbital period	2.66113 yr (971.977 d)
Physical characteristics
Dimensions	1 km (0.62 mi)
Mass	3.5×1012 kg
Mean density	2? g/cm³
Surface gravity	0.000 42 m/s²
Escape velocity	0.000 79 km/s
Albedo	0.15?
Temperature	~198 K
Spectral type	C or S
Absolute magnitude (H)	17.7

1221 Amor is the namesake of the Amor asteroids, a group of near-Earth asteroids whose orbits range between those of Earth and Mars. Amors are often Mars-crossers but they are not Earth-crossers.

Eugène Joseph Delporte photographed Amor as it approached Earth to within 16 million kilometers (about 40 times the distance from Earth to the moon); this was the first time that an asteroid was seen to approach Earth so closely. A month later, 1862 Apollo was seen to cross Earth's orbit, and the scientific community suddenly realised the potential threat these flying mountains presented.

Amor is named after the Roman god of love, better known as Cupid. See also 763 Cupido and 433 Eros, which is named after Cupid's Greek counterpart. Coincidentally, 433 Eros, like 1221 Amor, makes close approaches to Earth. It is a Mars-crosser as well.