| Orbital characteristics | |
|---|---|
| Orbit type | Near-Earth, 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 | 5d 9h 50m + 7d 8h 24m |
| Spectral class | S |
| Albedo | 0.13 |
| History | |
| Discoverer | C. Pollas, 1989 |
4179 Toutatis (asteroid 4179) is an Earth-crossing asteroid whose orbit, strongly influenced by Earth's gravity, is chaotic. 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.
On September 29 2004 Toutatis will pass within 4 lunar distances of Earth, presenting a good opportunity for observation.