4179 Toutatis was first sighted on February 10, 1934, as object 1934 CT, and then promptly lost. It remained a lost asteroid for several decades until it was recovered on January 4, 1989, by Christian Pollas, and was named after the Celtic god Toutatis/Teutates. Toutatis is an Apollo, Alinda, and Mars-crosser asteroid with a chaotic orbit produced by a 3:1 resonance with the planet Jupiter and 1:4 resonance with the planet Earth. Due to its very low orbital inclination (0.47°) and its orbital period of very nearly 4 years, Toutatis makes frequent close approaches to Earth, with a currently minimum possible distance (Earth MOID) of just 0.006 AU (2.3 times as far as the Moon).
The approach on September 29, 2004, was particularly close, at 0.0104 AU (within 4 lunar distances) from Earth, presenting a good opportunity for observation, with Toutatis shining at magnitude 8.9 when brightest. The most recent close approach of 0.0502 AU happened on November 9, 2008. The next close approach will be December 12, 2012, at a distance of around 0.04633 AU, and at magnitude 10.
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 hypothesized that Toutatis formed from two originally separate bodies which coalesced at some point, with the resultant asteroid being compared to a “rubble pile”.
The close pass in September 2004 was close enough to raise concerns that Toutatis would eventually collide with Earth. The likelihood of collision is considered to be small. As a planet-crossing asteroid, Toutatis is likely to be ejected from the Solar System on a time scale of a few tens of thousands of years, giving it a limited number of opportunities to strike Earth before disappearing forever.
So back to the information at hand… you might be asking yourself what is an AU? 1 A.U. is the average distance between the center of mass of the Earth and the center of mass of the Sun which comes out to be approximately 149,598,000 km (92,955,887.6 miles). Now we can use simple dimensional analysis to actually see how far Toutatis will be from the Earth on December 12, 2012.
0.04633 AU x 92,955,887.6 mi = 6,931,000 km (4,307,000 miles) from Earth.
So the asteroid will be 4.3 x 10^6 mi away from the Earth… is that close? Lets put that in to perspective by comparing it to the Earth-Moon average distance. The Earth-Moon distance is 384,403 km (238,857 miles) apart, meaning that Toutatis will be 18 times the distance of the Earth to the Moon. In our opinion, that’s not close enough to classify it as a Doomsday possibility… its even stretching it to call it a “close encounter”. So, with the information at hand we can safely say that the chances of Toutatis impacting the Earth on December 12, 2012 is 0%.