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 ...

in a

co-orbital configuration In astronomy, a co-orbital configuration is a configuration of two or more astronomical objects (such as asteroids, moons, or planets) orbiting at the same, or very similar, distance from their primary; i.e., they are in a 1:1 mean-motion resonanc ...

with Earth, classified as

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 ...

and potentially hazardous asteroid 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 ...

. It was discovered by the

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, List of observatory codes, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy Space observatory, space telescope in the Explorers Program launched in December 2009.. . WISE L ...

space telescope A space telescope (also known as space observatory) is a telescope in outer space used to observe astronomical objects. Suggested by Lyman Spitzer in 1946, the first operational telescopes were the American Orbiting Astronomical Observatory, OAO ...

(WISE) on 17 September 2010.

Description

The orbit was described by

Apostolos Christou Apostolos Christou (; born 1 November 1996) is a Greek swimmer specializing in backstroke. He is the Greek National Record holder in the 100 metre freestyle and 50, 100, and 200 metre backstroke events, as well as contributing to national reco ...

and David Asher at the

Armagh Observatory Armagh Observatory is an astronomical research institute in Armagh, Northern Ireland. Around 25 astronomers are based at the observatory, studying stellar astrophysics, the Sun, Solar System astronomy and Earth's climate. In 2018, Armagh Obs ...

Northern Ireland Northern Ireland ( ; ) is a Countries of the United Kingdom, part of the United Kingdom in the north-east of the island of Ireland. It has been #Descriptions, variously described as a country, province or region. Northern Ireland shares Repub ...

. The object has an absolute magnitude of 20.5. Observations by the discovering WISE telescope give a diameter of 357 meters and an

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

of 0.084. has a

horseshoe orbit In celestial mechanics, a horseshoe orbit is a type of co-orbital motion of a small orbiting body relative to a larger orbiting body. The osculating (instantaneous) orbital period of the smaller body remains very near that of the larger body, a ...

that allows it to stably share Earth's orbital neighborhood without colliding with it. It is one of a handful of known asteroids with an Earth-following orbit, a group that includes

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 ...

, and the only known asteroid in an horseshoe orbit with Earth. It is, however, neither an Aten asteroid nor 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 ...

because the

semi-major axis In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the longe ...

of its orbit is neither less than nor greater than 1 AU, but oscillates between approximately 0.996 and 1.004 AU, with a period of about 350 years. In its ~350 yr horseshoe cycle, it never approaches Earth more closely than about 0.15 AU, alternately trailing and leading. According to various simulations will remain in this orbit for at least 120,000 years and possibly for more than a million years, which is unusually stable compared to other similar objects. One reason for this stability is its low

orbital eccentricity In astrodynamics, the orbital eccentricity of an astronomical object is a dimensionless parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values be ...

< 0.084

. A

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 ...

of may have been located in a 2005

Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003, that was deactivated when operations ended on 30 January 2020. Spitzer was the third space telescope dedicate ...

image.

References

External links

* * * {{DEFAULTSORT:2010 SO16 419624 419624 419624 419624 419624 20100917 Horseshoe orbit

Description

See also

References

External links