2010 TK7
2010 TK7 is a sub-kilometer Near-Earth asteroid and the first Earth trojan discovered; it precedes Earth in its orbit around the Sun. Trojan objects are most easily conceived as orbiting at a Lagrangian point, a dynamically stable location (where the combined gravitational force acts through the Sun's and Earth's barycenter) 60 degrees ahead of or behind a massive orbiting body, in a type of 1:1 orbital resonance. In reality, they oscillate around such a point. Such objects had previously been observed in the orbits of Mars, Jupiter, Neptune, and the Saturnian moons Tethys and Dione.
Asteroid 2010 TK7 (circled in green) in image from the WISE spacecraft | |
| Discovery | |
|---|---|
| Discovered by | WISE spacecraft |
| Discovery site | LEO, polar orbit |
| Discovery date | 1 October 2010 |
| Designations | |
| |
| Orbital characteristics | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 768 days (2.10 yr) |
| Aphelion | 1.1903 AU (178.07 Gm) |
| Perihelion | 0.80918 AU (121.052 Gm) |
| 0.99972 AU (149.556 Gm) | |
| Eccentricity | 0.19059 |
| 1.00 yr (365.10 d) | |
Average orbital speed | 29.8 km/s |
| 354.14° | |
| 0° 59m 9.672s / day | |
| Inclination | 20.890° |
| 96.498° | |
| 45.927° | |
| Earth MOID | 0.0837911 AU (12.53497 Gm) |
| Physical characteristics | |
Mean diameter | 379±123 m |
| 0.059±0.049 | |
| 20.8 (when near Earth) to 23.6 | |
| 20.8 | |
2010 TK7 has a diameter of about 300 meters (1,000 ft). Its path oscillates about the Sun–Earth L4 Lagrangian point (60 degrees ahead of Earth), shuttling between its closest approach to Earth and its closest approach to the L3 point (180 degrees from Earth).
The asteroid was discovered in October 2010 by the NEOWISE team of astronomers using NASA's Wide-field Infrared Survey Explorer (WISE).