2010 SO16
Encyclopedia
is a near-Earth asteroid
discovered by the Wide-field Infrared Survey Explorer
space telescope. The orbit was described by Christou Apostolos and David Asher at the Armagh Observatory
in Ireland
. The object has a magnitude
of 20.7 and is several hundred meters in diameter.
has a "horseshoe orbit
" that allows it to stably share Earth's orbital neighborhood without colliding with it. It is one of a handful of known asteroids with such an orbit, a group that includes 3753 Cruithne
. It is, however, neither an Aten asteroid
nor an Apollo asteroid
because the semi-major axis
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 yr. In its ~350 yr horseshoe cycle, it never approaches the 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
,
.
Near-Earth object
A near-Earth object is a Solar System object whose orbit brings it into close proximity with the Earth. All NEOs have a perihelion distance less than 1.3 AU. They include a few thousand near-Earth asteroids , near-Earth comets, a number of solar-orbiting spacecraft, and meteoroids large enough to...
discovered by the Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer is a NASA infrared-wavelength astronomical space telescope launched on December 14, 2009, and decommissioned/hibernated on February 17, 2011 when its transmitter was turned off...
space telescope. The orbit was described by Christou Apostolos and David Asher at the Armagh Observatory
Armagh Observatory
Armagh Observatory is a modern astronomical research institute with a rich heritage, based in Armagh, Northern Ireland. Around 25 astronomers are actively studying stellar astrophysics, the Sun, Solar System astronomy, and the Earth's climate....
in Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
. The object has a magnitude
Magnitude (astronomy)
Magnitude is the logarithmic measure of the brightness of an object, in astronomy, measured in a specific wavelength or passband, usually in optical or near-infrared wavelengths.-Background:...
of 20.7 and is several hundred meters in diameter.
has a "horseshoe orbit
Horseshoe orbit
A horseshoe orbit is a type of co-orbital motion of a small orbiting body relative to a larger orbiting body . The orbital period of the smaller body is very nearly the same as for the larger body, and its path appears to have a horseshoe shape in a rotating reference frame as viewed from the...
" that allows it to stably share Earth's orbital neighborhood without colliding with it. It is one of a handful of known asteroids with such an orbit, a group that includes 3753 Cruithne
3753 Cruithne
3753 Cruithne is an asteroid in orbit around the Sun in approximate 1:1 orbital resonance with the Earth. It is a periodic inclusion planetoid orbiting the Sun in an apparent horseshoe orbit. It has been incorrectly called "Earth's second moon", but it is only a quasi-satellite. Cruithne never...
. It is, however, neither an Aten asteroid
Aten asteroid
The Aten asteroids are a group of near-Earth asteroids, named after the first of the group to be discovered . They are defined by having semi-major axes of less than one astronomical unit...
nor an Apollo asteroid
Apollo asteroid
The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, the first asteroid of this group to be discovered by Karl Wilhelm Reinmuth...
because the semi-major axis
Semi-major axis
The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape...
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 yr. In its ~350 yr horseshoe cycle, it never approaches the 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
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...
,
.See also
- 3753 Cruithne3753 Cruithne3753 Cruithne is an asteroid in orbit around the Sun in approximate 1:1 orbital resonance with the Earth. It is a periodic inclusion planetoid orbiting the Sun in an apparent horseshoe orbit. It has been incorrectly called "Earth's second moon", but it is only a quasi-satellite. Cruithne never...
– a horseshoeHorseshoe orbitA horseshoe orbit is a type of co-orbital motion of a small orbiting body relative to a larger orbiting body . The orbital period of the smaller body is very nearly the same as for the larger body, and its path appears to have a horseshoe shape in a rotating reference frame as viewed from the...
companion of the Earth – a small asteroid that sometimes temporarily gets caught in Earth orbit – a horseshoe companion of the Earth - Natural satelliteNatural satelliteA natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....