2020 PN1

2020 PN₁

Discovery
Discovered by	ATLAS-HKO
Discovery site	Haleakalā Observatory
Discovery date	12 August 2020
Designations
Designation	2020 PN1
Minor planet category	Aten NEO [1] [2] Earth crosser
Orbital characteristics [2] [3] [4]
Epoch 31 May 2020 (JD  2459000.5)
Uncertainty parameter 0
Observation arc	361 days
Aphelion	1.12482093  AU
Perihelion	0.8713906 AU
Semi-major axis	0.998105754 AU
Eccentricity	0.1269557
Orbital period (sidereal)	1.00  y (364.219560  d)
Mean anomaly	32.06964°
Inclination	4.80807°
Longitude of ascending node	145.63610°
Argument of perihelion	55.40365°
Earth  MOID	0.0248258 AU
Physical characteristics
Dimensions	10–50 m [a] [5]
Absolute magnitude (H)	25.5 [2]

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]

Discovery

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

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

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

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

• 54509 YORP
• (419624) 2010 SO16
• 3753 Cruithne
• 2015 SO2
• 2015 XX169
• 2015 YQ1
• 2015 YA

Notes

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

References

1. List Of Aten Minor Planets
2. 2020 PN1 at the JPL Small-Body Database
   • Close approach  · Discovery  · Ephemeris  · Orbit viewer  · Orbit parameters  · Physical parameters
   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. 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

• Bottke, William F.; Jedicke, Robert; Morbidelli, Alessandro; Petit, Jean-Marc; Gladman, Brett (June 2000). "Understanding the Distribution of Near-Earth Asteroids". Science . 288 (5474): 2190–2194. Bibcode:2000Sci...288.2190B. doi:10.1126/science.288.5474.2190. ISSN   0036-8075. PMID   10864864.
• Christou, Apostolos A. (March 2000). "A Numerical Survey of Transient Co-orbitals of the Terrestrial Planets". Icarus . 144 (1): 1–20. Bibcode:2000Icar..144....1C. doi:10.1006/icar.1999.6278.
• Bottke, William F.; Morbidelli, Alessandro; Jedicke, Robert; Petit, Jean-Marc; Levison, Harold F.; Michel, Patrick; Metcalfe, Travis S. (April 2002). "Debiased Orbital and Absolute Magnitude Distribution of the Near-Earth Objects". Icarus . 156 (2): 399–433. Bibcode:2002Icar..156..399B. doi:10.1006/icar.2001.6788. ISSN   0019-1035.
• Brasser, R.; Innanen, K. A.; Connors, M.; Veillet, C.; Wiegert, P.; Mikkola, Seppo; Chodas, P. W. (September 2004). "Transient co-orbital asteroids". Icarus . 171 (1): 102–109. Bibcode:2004Icar..171..102B. doi:10.1016/j.icarus.2004.04.019. ISSN   0019-1035.
• de la Fuente Marcos, C.; de la Fuente Marcos, R. (April 2016). "A trio of horseshoes: past, present and future dynamical evolution of Earth co-orbital asteroids 2015 XX₁₆₉, 2015 YA and 2015 YQ₁". Astrophysics and Space Science . 361 (4) 121. arXiv: 1603.02415 . Bibcode:2016Ap&SS.361..121D. doi:10.1007/s10509-016-2711-6. ISSN   0004-640X.

External links

• Discovery MPEC
• 2020 PN₁ data at MPC
• 2020 PN1 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemerides  · Observation prediction  · Orbital info  · MOID  · Proper elements  · Observational info  · Close approaches  · Physical info  · Orbit animation
• 2020 PN1 at ESA–space situational awareness
  • Ephemerides  · Observations  · Orbit  · Physical properties  · Summary
• 2020 PN1 at the JPL Small-Body Database
  • Close approach  · Discovery  · Ephemeris  · Orbit viewer  · Orbit parameters  · Physical parameters