4179 Toutatis
The asteroid 4179 Toutatis is an Apollo, an Alinda and a Mars-crosser asteroid with a chaotic orbit produced by a 3:1 resonance with the planet Jupiter. 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, with a minimum distance at present of just 0.006 AU. The approach 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.
Its rotation combines two separate periodic motions into a non-periodic result; to someone on the surface of Toutatis the Sun would seem to rise and set in apparently random locations and at random times at the asteroid's horizon.
It was discovered on January 4, 1989 by Christian Pollas and was named after the Celtic deity Toutatis, a Gallic war god.
Radar imagery has shown that Toutatis is a highly irregular body consisting of two distinct "lobes", with maximum widths of about 4.6 km and 2.4 km respectively. It is theorized that Toutatis formed from two originally separate bodies which coalesced at some point, with the resultant asteroid being compared to a "rubble pile".
Related topics
