2022 RM4

2022 RM₄ is categorized as a potentially hazardous asteroid because it is around 400 meters in diameter^[3][a] and makes close approaches to Earth. It was discovered on 12 September 2022 when it was 0.61 AU (91 million km) from Earth and located at declination +65 near the northern circumpolar star Zeta Draconis.^[1]

2022 RM₄

The orbit of 2022 RM4 is highly inclined at 38° and takes 3.8 years to orbit the Sun.
Discovery[1]
Discovered by	Pan-STARRS 2
Discovery date	12 September 2022
Designations
MPC designation	2022 RM4
Minor planet category	Apollo NEO PHA[2]
Orbital characteristics[2]
Epoch 2022-Aug-09 (JD 2459800.5)
Uncertainty parameter 5
Observation arc	50 days
Aphelion	3.90 AU (Q)
Perihelion	0.98844 AU (q)
Semi-major axis	2.446 AU (a)
Eccentricity	0.596 (e)
Orbital period (sidereal)	3.83 years
Mean anomaly	337.8° (M)
Inclination	38.31° (i)
Longitude of ascending node	218.2° (Ω)
Time of perihelion	3 November 2022
Argument of perihelion	181.7° (ω)
Earth MOID	0.0032 AU (480 thousand km; 1.2 LD)
Jupiter MOID	1.5 AU (220 million km)
Physical characteristics
Dimensions	≈400 m (1,000 ft)[3][a] 290–650 meters[b]
Absolute magnitude (H)	19.8[4]

At 1 November 2022 18:26 UT it passed 0.01536 AU (2,298,000 km; 5.98 LD) from Earth.^[2] As of 1 November 2022 the uncertainty in the close approach distance was ±77 km.^[5] The asteroid should have brighten to about apparent magnitude 14.3 which is roughly the brightness of Pluto and was around 75 degrees from the Sun.^[6] It may have been viewable by experienced amateur observers with a telescope that has an aperture of around 8-inches or better.^[7]

Earth Approach on 1 November 2022^[2]

Date	JPL Horizons nominal geocentric distance (AU)	uncertainty region (3-sigma)
2022-11-01 18:26 ± 00:01	0.01536 AU (2.298 million km)[2]	±77 km[8]

By 2 November 2022 the asteroid was better placed for the southern hemisphere with a declination of –32.^[6] Goldstone Solar System Radar using the Canberra Deep Space Communication Complex 70–meter Deep Space Station 43 and Australia Telescope Compact Array observed the asteroid on 2 November 2022.^[9] It then came to perihelion (closest approach to the Sun) on 3 November 2022.^[2]

See also

• List of asteroid close approaches to Earth in 2022 beyond 1 LD
• List of asteroid close approaches to Earth in 2023 beyond 1 LD
• 2015 TB145

Notes

1. An absolute magnitude of 19.8 and assumed albedo of 0.14 gives a diameter of 389 meters (or ≈400 meters after rounding).
2. Diameter range based on Minor Planet Center absolute magnitude value of 19.8 and assumed albedo range of 0.25 to 0.05.