4179 Toutatis
 A 3D model of the different faces of Toutatis | |
| Orbital characteristics | |
|---|---|
| Orbit type | Alinda, chaotic |
| Semimajor axis | 2.511 AU |
| Eccentricity | 0.634 |
| Orbital period | 3.98 years |
| Inclination | 0.47 ° |
| Physical characteristics | |
| Diameter | 4.5×2.4×1.9 km |
| Mass | 5.0×1013 kg |
| Density | 2.1 g/cm3 |
| Rotation period | 5 day 9 h 50 min + 7 day 8 h 24 min |
| Spectral class | S |
| Albedo | 0.13 |
| History | |
| Discoverer | C. Pollas, 1989 |
The asteroid 4179 Toutatis is an Alinda asteroid with a chaotic orbit caused by the strong influence of Earth's gravity. Furthermore, its rotation combines two separate periodic motions that combine to produce a nonperiodic rotation; to someone on the surface of Toutatis the Sun would seem to rise and set in apparently random locations and times at the asteroid's horizon.
It was discovered in 1989 by Christian Pollas.
Due to its very low orbital inclination (0.47°) and its orbital period of 3.99 years (almost an integer number of years), Toutatis makes close approaches to Earth every four years. The one on September 29, 2004 will be particularly close, at 0.0104 AU (within 4 lunar distances) from Earth, presenting a good opportunity for observation. The next approach after that will be November 9 2008 at 0.0503 AU.
4179 Toutatis was named after the Celtic god Toutatis that was the protector of the tribe in ancient Gaul.