Astronomy: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 Earth crosser
Orbital characteristics
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc	361 days
|{{{apsis}}}|helion}}	1.12482093 AU
|{{{apsis}}}|helion}}	0.8713906 AU
Semi-major axis	0.998105754 AU
Eccentricity	0.1269557
Orbital period	1.00 y (364.219560 d)
Mean anomaly	32.06964°
Inclination	4.80807°
Longitude of ascending node	145.63610°
|{{{apsis}}}|helion}}	55.40365°
Earth MOID	0.0248258 AU
Physical characteristics
Dimensions	10–50 m
Absolute magnitude (H)	25.5

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.

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. As of 20 January 2021, it has been observed 41 times with an observation arc of 361 days.

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.

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. However, in April 2023, the new target is 2019 VL₅.

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

Further reading

• Understanding the Distribution of Near-Earth Asteroids Bottke, W. F., Jedicke, R., Morbidelli, A., Petit, J.-M., Gladman, B. 2000, Science, Vol. 288, Issue 5474, pp. 2190–2194.
• A Numerical Survey of Transient Co-orbitals of the Terrestrial Planets Christou, A. A. 2000, Icarus, Vol. 144, Issue 1, pp. 1–20.
• Debiased Orbital and Absolute Magnitude Distribution of the Near-Earth Objects Bottke, W. F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H. F., Michel, P., Metcalfe, T. S. 2002, Icarus, Vol. 156, Issue 2, pp. 399–433.
• Transient co-orbital asteroids Brasser, R., Innanen, K. A., Connors, M., Veillet, C., Wiegert, P., Mikkola, S., Chodas, P. W. 2004, Icarus, Vol. 171, Issue 1, pp. 102–109.
• A trio of horseshoes: past, present and future dynamical evolution of Earth co-orbital asteroids 2015 XX₁₆₉, 2015 YA and 2015 YQ₁ de la Fuente Marcos, C., de la Fuente Marcos, R. 2016, Astrophysics and Space Science, Vol. 361, Issue 4, article 121 (13 pp).

External links

• Discovery MPEC
• 2020 PN₁ data at MPC
• 2020 PN1 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
• 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 diagram · Orbital elements · Physical parameters