is a sub-kilometer
asteroid
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...
, classified as a
near-Earth object
A near-Earth object (NEO) is any small Solar System body orbiting the Sun whose closest approach to the Sun ( perihelion) is less than 1.3 times the Earth–Sun distance (astronomical unit, AU). This definition applies to the object's orbit a ...
of the
Apollo group
Apollo Education Group, Inc. is an American corporation based in the South Phoenix area of Phoenix, Arizona, with an additional corporate office in Chicago, Illinois. It is privately-owned by a consortium of investors including The Vistria Grou ...
, that is a stable
quasi-satellite
A quasi-satellite is an object in a specific type of co-orbital configuration (1:1 orbital resonance) with a planet (or dwarf planet) where the object stays close to that planet over many orbital periods.
A quasi-satellite's orbit around the Sun ...
of the
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
. There are over a dozen known Earth quasi-satellites, some of which switch periodically between the quasi-satellite and horseshoe co-orbital states.
Discovery
was discovered on 12 August 2020 by the
Pan-STARRS
The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1; List of observatory codes, obs. code: IAU code#F51, F51 and Pan-STARRS2 obs. code: IAU code#F52, F52) located at Haleakala Observatory, Hawaii, US, consists of astronomical ...
1 survey at the
Haleakalā Observatory
The Haleakalā Observatory, also known as the Haleakalā High Altitude Observatory Site, is Hawaii's first astronomical research observatory. It is located on the island of Maui and is owned by the Institute for Astronomy of the University of Ha ...
.
It was later recovered by the
Karl Schwarzschild Observatory
The Karl Schwarzschild Observatory (Officially: ''Thuringia State Observatory Tautenburg'') is a German astronomy, astronomical observatory in Tautenburg near Jena, Thuringia. It is owned and operated as under public law by the Thuringia, State of ...
in August 2021, which allowed for
precovery
In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of a celestial object in images or photographic plates predating its discovery, typically for the purpose of calculating a more accurate orbit. This ha ...
in earlier Pan-STARRS observations from 24 July 2017.
Orbit and orbital evolution
is currently an
Apollo asteroid
The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, discovered by German astronomer Karl Reinmuth in the 1930s. They are Earth-crossing asteroids that have an orbital semi-major axis greater than that of the Ear ...
(Earth-crossing but with a period longer than a year). Its semi-major axis (currently 1.001715
AU) is similar to that of
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
(0.999789 AU), but it has both low eccentricity (0.07384) and low orbital inclination (5.827°). It alternates between being an
Aten asteroid and being an
Apollo asteroid
The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, discovered by German astronomer Karl Reinmuth in the 1930s. They are Earth-crossing asteroids that have an orbital semi-major axis greater than that of the Ear ...
, although its orbital evolution is not fully stable and it can be considered as a temporary quasi-satellite of the Earth; its orbital evolution is akin to that of
469219 Kamooalewa.
Physical properties
With an
absolute magnitude of 26.6, it has a diameter in the range 10–30 meters (for an assumed albedo range of 0.20–0.04 respectively).
See also
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3753 Cruithne
3753 Cruithne is a Q-type, Aten asteroid in orbit around the Sun in 1:1 orbital resonance with Earth, making it a co-orbital object. It is an asteroid that, relative to Earth, orbits the Sun in a bean-shaped orbit that effectively describes a ...
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54509 YORP
54509 YORP ( provisional designation ) is an Earth co-orbital asteroid discovered on 3 August 2000 by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) Team at Lincoln Laboratory Experimental Test Site in Socorro, New Mexico. Measur ...
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469219 Kamooalewa
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References
Further reading
Understanding the Distribution of Near-Earth AsteroidsBottke, 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 PlanetsChristou, A. A. 2000, ''Icarus'', Vol. 144, Issue 1, pp. 1–20.
Debiased Orbital and Absolute Magnitude Distribution of the Near-Earth ObjectsBottke, 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 asteroidsBrasser, 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 YQ1de la Fuente Marcos, C., de la Fuente Marcos, R. 2016, ''Astrophysics and Space Science'', Vol. 361, Issue 4, article 121 (13 pp).
External links
data at MPC
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Horseshoe orbit