An asteroid called "4179 Toutatis (1989 AC)" is largest known Potentially Hazardous Asteroid (PHA) popularly known as Toutatis will flyby earth at distance of 69,31,175 km (the closest it can get this time near Earth) on 12th Dec 2012 at 12:10 pm noon IST. Size of this asteroid is 5.4 km. And it’s moving at speed of 11.9 km/sec. This asteroid was discovered in 4 Jan 1989 and was named after the Celtic god worshipped in ancient Britain as Toutatis/Teutates (the tribal protector).
Details of the ASTEROID 4179 Toutatis (1989 AC):
This asteroid orbits Sun every 4.02 years or 1469 days.
The next time it will have closest approach is in 29th December 2016 and would be at 3,75,78,442 Km. Whereas last time it came close was on 9th November 2008 and was at 75,16,979km). After 2016 this asteroid will not pass close to Earth again until 2069.
The minimum distance also termed as Earth MOID or it can get close to earth if possible is 8,97,587 km. On 28 September 2004 it missed us by 15,55,817 km and was object for fear mongering by some doomsayers then.
Not visible to Naked Eye – Telescopes – Professionals: this asteroid is presently shining at 10 Magnitude. And Healthy human eye can see upto max. 6 Magnitude objects in sky. Hence not visible to naked eye
OTHER DETAILS :
No Danger of Collision – Opportunity for Studies: Though it is listed as “Potentially Hazardous Asteroid” the chance of collision with earth now or in future is very less. No other kilometer-sized PHA moves around the Sun in an orbit so nearly coplanar with our own. This makes it an important target for asteroid studies. Its expected that present Radar observations would improve researchers' ability to predict the asteroid's trajectory even farther into the future. Goldstone observatory will follow Toutatis and ping until Dec. 22nd 2012.
This asteroid has visited us many times in the past. As a planet-crossing asteroid, Toutatis is likely to be ejected from the inner Solar System with a time scale of a few million years or less, giving it a limited number of opportunities to strike Earth before disappearing forever.
Chaotic Behavior – thanks to Planets: chaotic behavior in the orbit of Toutatis is due to gravitational perturbations caused by frequent close approaches to the terrestrial planets and makes precise long-term predictions of its location progressively inaccurate over time.
First Sighted – Lost and Found – Discovery – Composition : It was first was first sighted on February 10, 1934, and was known as object 1934 CT, and then promptly lost. It remained a lost asteroid for several decades until it was recovered/Discovered on January 4, 1989, by Christian Pollas. Studies suggest it to consist primarily of silicates because based on it spectral properties it is categorized as an S-type, or stony asteroid.
Opportunity for Studies – Chinese Mission & Others : Toutatis has been observed with radar imaging from the Arecibo Observatory and the Goldstone Solar System Radar during the asteroid's prior Earth flybys in 1992, 1996, 2000, 2004, and 2008 and same is planned for year 2012.