2020 OY4

2020 OY₄
Discovery
Discovered by	MLS
Discovery site	Mount Lemmon Obs.
Discovery date	July 26, 2020
Designations
MPC designation	2020 OY4
Minor planet category	NEO · Apollo
Orbital characteristics
	Epoch 31 May 2020 (JD 2459000.5)
	Uncertainty parameter 6 · 7
Observation arc	2 days
Aphelion	1.5623 AU
Perihelion	0.6873 AU
Semi-major axis	1.1248 AU
Eccentricity	0.3889
Orbital period (sidereal)	1.19 yr (436 d)
Mean anomaly	257.94°
Mean motion	0° 49m 34.32s / day
Inclination	2.1148°
Longitude of ascending node	305.50°
Argument of perihelion	98.703°
Earth MOID	0.0000879 AU (0.034 LD)
Physical characteristics
Mean diameter	2–5 m
Absolute magnitude (H)	30.18; 30.35

2020 OY₄ is a very small asteroid classified as a near-Earth object that passed within 21,850 miles (35,160 km) of the surface of Earth on July 28, 2020, with a fly-by speed of 12.4 kilometres (7.7 mi) per second. The car-sized asteroid posed no risk of impact to Earth, but it did pass within the orbit of satellites in the geostationary ring at 35,785 kilometres (22,236 mi) above Earth's equator.

The asteroid was discovered July 26, 2020 using the Mount Lemmon Survey telescope in the Santa Catalina Mountains northeast of Tucson, Arizona. The next encounter closer than the Moon is predicted to occur July 30, 2055 at a distance of 200,000 kilometres (124,000 mi) or more.