Asteroid 4179, a member of the Apollo group, discovered in 1989 by the French astronomer Christian Pollas (1947– ). At present, Toutatis can approach to 0.006 au (900 000 km) of the Earth’s orbit. Of the largest near-Earth asteroids, Toutatis is perhaps the most potentially dangerous to the Earth in the foreseeable future, because of its frequent approaches plus a 3 : 1 resonance with Jupiter which makes the orbit chaotic. Radar observations show that it consists of two irregular, cratered bodies in close contact, with maximum widths of about 4.2 km and 2.0 km, respectively. Its orbit has a semimajor axis of 2.53 au, period 4.04 years, perihelion 0.94 au, aphelion 4.13 au, and inclination 0°.4.