|Discovered by||Wide-field Infrared Survey Explorer|
|Epoch January 4, 2010 (2455200.5)|
|Aphelion||1.058 AU (Q)|
|Semi-major axis||1.00039 AU (a)|
|Mean anomaly||137.831° (M)|
|Longitude of ascending node||40.523°|
|Argument of perihelion||108.283°|
|Absolute magnitude (H)||20.7|
2010 SO16 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 Northern Ireland. The object has a magnitude of 20.7 and is several hundred meters in diameter.
2010 SO16 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 2010 SO16 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, .
- 3753 Cruithne – a horseshoe companion of the Earth
- 2006 RH120 – a small asteroid that sometimes temporarily gets caught in Earth orbit
- 2002 AA29 – a horseshoe companion of the Earth
- Natural satellite
References and footnotes