3753 Cruithne
| Discovery | |
|---|---|
| Discovered by | Duncan Waldron |
| Discovery date | 10 October 1986 |
| Designations | |
| (3753) Cruithne | |
| Pronunciation | English: /kruˈiːnjə/ kroo-EEN-yə Irish: [ˈkɾˠɪ(h)nʲə, ˈkɾˠʊnʲə] |
Named after | Cruthin |
| 1983 UH; 1986 TO | |
| Orbital characteristics | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 16087 days (44.04 yr) |
| Aphelion | 1.5114 AU (226,100,000 km) |
| Perihelion | 0.48405 AU (72,413,000 km) |
| 0.99774 AU (149,260,000 km) | |
| Eccentricity | 0.51485 (213000 wrt Earth) |
| 1.00 yr (364.02 d) | |
Average orbital speed | 27.73 km/s |
| 257.46° | |
| 0° 59m 20.436s / day | |
| Inclination | 19.805° |
| 126.23° | |
| 43.831° | |
| Earth MOID | 0.07119 AU (10,650,000 km) |
| Physical characteristics | |
| ~5 km | |
| Mass | 1.3×1014 kg |
| 27.30990 h (1.137913 d) | |
| 0.15 | |
| Q | |
| 15.6 | |
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 horseshoe, and that can change into a quasi-satellite orbit. Cruithne does not orbit Earth and at times it is on the other side of the Sun, placing Cruithne well outside of Earth's Hill sphere. Its orbit takes it near the orbit of Mercury and outside the orbit of Mars. Cruithne orbits the Sun in about one Earth year, but it takes 770 years for the series to complete a horseshoe-shaped movement around Earth.
The asteroid takes its name from the Cruithne, a people mentioned in early Irish annals.