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]
 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 | |
| 2022 RM4 | |
| 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) |
| 2.446 AU (a) | |
| Eccentricity | 0.596 (e) |
| 3.83 years | |
| 337.8° (M) | |
| Inclination | 38.31° (i) |
| 218.2° (Ω) | |
| 3 November 2022 | |
| 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 | |
| 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]
| 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
editNotes
edit- ^ a b An absolute magnitude of 19.8 and assumed albedo of 0.14 gives a diameter of 389 meters (or ≈400 meters after rounding).
- ^ Diameter range based on Minor Planet Center absolute magnitude value of 19.8 and assumed albedo range of 0.25 to 0.05.
References
edit- ^ a b "MPEC 2022-R162 : 2022 RM4". IAU Minor Planet Center. 25 September 2022. Retrieved 9 October 2022. (K22R04M)
- ^ a b c d e f "JPL Small-Body Database Browser: (2022 RM4)". Jet Propulsion Laboratory. Retrieved 28 October 2022.
- ^ a b "ESA Summary: 2022RM4". European Space Agency. Archived from the original on 9 October 2022. Retrieved 9 October 2022.
- ^ "2022 RM4 Orbit". Minor Planet Center. Archived from the original on 31 October 2022. Retrieved 31 October 2022.
- ^ Archive of JPL Horizons using JPL #24 solution date 2022-Nov-01
- ^ a b "Magnitude near 2022-11-01 close approach". JPL Horizons. Retrieved 9 October 2022.
- ^ Kelly Kizer Whitt (5 October 2022). "Large asteroid RM4 to pass closely November 1". Earthsky. Retrieved 9 October 2022.
- ^ "Horizons Batch for 2022-11-01 Close Approach". JPL Horizons. Archived from the original on 9 October 2022. Retrieved 1 November 2022. RNG_3sigma = uncertainty range in km. (JPL#24/Soln.date: 2022-Nov-01 generates RNG_3sigma = 77 km)
- ^ Dr. Lance A. M. Benner. "Goldstone Asteroid Schedule". NASA Asteroid Radar Research. Retrieved 28 October 2022.
External links
edit- Animation showing 2022RM4 approach from the Northern Hemisphere and exit the Southern Hemisphere – Tony Dunn
- Potentially Hazardous Asteroid 2022 RM4 close encounter: a image – 14 Oct. 2022
- 2022 RM4 at NeoDyS-2, Near Earth Objects—Dynamic Site
- 2022 RM4 at ESA–space situational awareness
- 2022 RM4 at the JPL Small-Body Database