2020 PN1 is a sub-kilometer asteroid, classified as a near-Earth object of the Aten group, that is a temporary horseshoe companion to the Earth. There are dozens of known Earth horseshoe librators, some of which switch periodically between the quasi-satellite and the horseshoe co-orbital states.[6]

2020 PN1
Discovery
Discovered byATLAS-HKO
Discovery siteHaleakalā Observatory
Discovery date12 August 2020
Designations
Designation
2020 PN1
Orbital characteristics[2][3][4]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc361 days
Aphelion1.12482093 AU
Perihelion0.8713906 AU
0.998105754 AU
Eccentricity0.1269557
1.00 y (364.219560 d)
32.06964°
Inclination4.80807°
145.63610°
55.40365°
Earth MOID0.0248258 AU
Physical characteristics
Dimensions10–50 m[a][5]
25.5[2]

Discovery

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2020 PN1 was discovered on 12 August 2020 by L. Denneau, J. Tonry, A. Heinze, and H. Weiland observing for the ATLAS-HKO Survey.[7] As of 20 January 2021, it has been observed 41 times with an observation arc of 361 days.[2]

Orbit and orbital evolution

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2020 PN1 is currently an Aten asteroid (Earth-crossing but with a period less than a year). Its semi-major axis (currently 0.998105754 AU) is similar to that of Earth (0.999789 AU), but it has a moderate eccentricity (0.1269557) and low orbital inclination (4.80807°). It alternates between being an Aten asteroid and being an Apollo asteroid, although its orbital evolution is not fully stable and it can be considered as a temporary co-orbital companion to the Earth.[6]

Physical properties

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With an absolute magnitude of 25.5 mag, it has a diameter in the range 10–50 meters (for an assumed albedo range of 0.04–0.20, respectively).

Exploration

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2020 PN1 was pre-selected for an exploration by a Chinese mission of planetary defense including an impactor and a separate orbiter planned to launch in 2026.[8] However, in April 2023, the new target is 2019 VL5.[9]

See also

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Notes

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  • ^ This is assuming an albedo of 0.20–0.04.

References

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  1. ^ List Of Aten Minor Planets
  2. ^ a b c d 2020 PN1 at the JPL Small-Body Database Retrieved 2021-01-20
  3. ^ AstDys-2 on 2020 PN1 Retrieved 2021-01-20
  4. ^ NEODyS-2 on 2020 PN1 Retrieved 2021-01-20
  5. ^ Absolute-magnitude conversion table (H)
  6. ^ a b de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (March 2021). "Using Mars co-orbitals to estimate the importance of rotation-induced YORP break-up events in Earth co-orbital space". Monthly Notices of the Royal Astronomical Society. 501 (4): 6007–6025. arXiv:2101.02563. Bibcode:2021MNRAS.501.6007D. doi:10.1093/mnras/stab062.
  7. ^ Discovery MPEC
  8. ^ Andrew Jones (July 12, 2022). "China to target near-Earth object 2020 PN1 for asteroid deflection mission". SpaceNews. Retrieved September 29, 2022.
  9. ^ Andrew Jones (April 11, 2023). "China to target asteroid 2019 VL5 for 2025 planetary defense test". SpaceNews. Retrieved April 21, 2023.
Further reading
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