(501647) 2014 SD₂₂₄

Collage of radar images taken by Goldstone on 26 December 2020
Discovery[1]
Discovered by	Pan-STARRS
Discovery date	22 September 2014
Designations
MPC designation	(501647) 2014 SD224
Minor planet category	Aten NEO[2]
Orbital characteristics[2]
Epoch 2020-May-31 (JD 2459000.5)
Uncertainty parameter 1
Observation arc	6.3 years
Aphelion	1.3015 AU
Perihelion	0.65406
Semi-major axis	0.97779 AU
Eccentricity	0.33107
Orbital period (sidereal)	353.15 days (0.97 years)
Mean anomaly	75.398°
Inclination	4.5484°
Longitude of ascending node	286.44°
Argument of perihelion	277.11°
Earth MOID	0.017 AU (2.5 million km)
Venus MOID	0.024 AU (3.6 million km)
Jupiter MOID	3.66 AU (548 million km)
Physical characteristics
Mean diameter	92–210 meters (CNEOS) ~150 m (490 ft)
Absolute magnitude (H)	22.3[2]

(501647) 2014 SD₂₂₄ is an Aten near-Earth asteroid around 150 meters (490 feet) in diameter. It was discovered on 22 September 2014 when the asteroid was 0.29 AU (43 million km; 110 LD) from Earth and had a solar elongation of 123 degrees. The glare of the Sun had masked the approach of the asteroid as it passed closest approach to Earth on 11 August 2014.^[2][a] The asteroid now has a 6-year observation arc and a well-determined orbit. It also makes close approaches to Venus.

2020

2014 SD₂₂₄ was less than 90 degrees from the Sun until September 2020 when it still had a very faint apparent magnitude of 24. The asteroid was recovered on 22 November 2020 by Mt. Lemmon Survey. The asteroid came to opposition (opposite the Sun in the sky) on 12 December 2020 when it had a solar elongation of 149 degrees and a magnitude of 18.^[3] It reached a peak brightness on 23 December 2020 at magnitude 16.4, which is still fainter than Pluto.

The asteroid safely passed closest approach to Earth on 25 December 2020 at 20:20 UT at a distance of 0.02 AU (3.0 million km; 7.8 LD).^[2] The 2020 close approach distance is known with an accuracy of roughly ±20 km.