(419624) 2010 SO16 is a sub-kilometer asteroid in a co-orbital configuration with Earth, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It was discovered by the Wide-field Infrared Survey Explorer space telescope (WISE) on 17 September 2010.[1][2]
Orbit with inner solar system
| |
| Discovery[1] | |
|---|---|
| Discovered by | WISE |
| Discovery site | Low Earth orbit |
| Discovery date | 17 September 2010 |
| Designations | |
| (419624) 2010 SO16 | |
| 2010 SO16 | |
| Apollo · NEO · PHA[1][2] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 5.28 yr (1,928 days) |
| Aphelion | 1.0785 AU |
| Perihelion | 0.9272 AU |
| 1.0028 AU | |
| Eccentricity | 0.0754 |
| 1.00 yr (367 days) | |
| 173.30° | |
| 0° 58m 53.04s / day | |
| Inclination | 14.520° |
| 40.397° | |
| 108.99° | |
| Earth MOID | 0.0299 AU (11.6 LD) |
| Physical characteristics | |
| 0.357±0.126km[3] | |
| 0.084±0.057[4] | |
| 20.5[1] | |
The orbit was described by Apostolos Christou and David Asher at the Armagh ObservatoryinNorthern Ireland.[5] The object has an absolute magnitude of 20.5.[1] Observations by the discovering WISE telescope give a diameter of 357 meters and an albedo of 0.084.[3][4]
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 an Earth-following orbit, a group that includes 3753 Cruithne, and the only known asteroid in an horseshoe orbit with Earth. 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 years.[5] 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 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.[6] One reason for this stability is its low orbital eccentricity, 
Aprecoveryof2010 SO16 may have been located in a 2005 Spitzer Space Telescope image.[7]
