Next week the attention of astronomers around the world will be glued to a giant asteroid, but not because he is a danger.

4179 Toutatis length 4,46 km and a width of 2.4 km - one of the largest asteroids observed near the Ground. on December 12 it pass us by 6.9 million km (more than 18 distances from the earth to the moon).

A computer model of Toutatis (image by Michael Busch).

Astronomers are particularly interested in rotation of the body such forms. Michael W. Bush from the National radio astronomy Observatory (USA), examined data about the asteroid received during his previous visits (they happen every four years), says: "It is turn somersaults, that is, revolves around the long axis, which, in turn, performs a circular motion, like a gyroscope (this phenomenon is known as the precession)".

Mr. Bush and his colleagues planned to Refine the model rotation Toutatis, created in 1996, but it turned out that one of the data analysis for the years 2000, 2004 and 2008 is not enough. Whenever the asteroid is approaching the Sun or Earth, they gently pulling it on yourself, changing the rotation. The effect is very small, but over the years, he added. Only after scientists were able to accommodate these changes, they have turned a new, refined model. And she told me how is the mass of the asteroid.

Toutatis simultaneously like lumpy peanuts and (under a certain angle) awkwardly stuck snowman. It is long and narrow, with two clearly distinguished shares of unequal size. The group Mr. Bush found out that the mass of an object is distributed unevenly, indicating a complex internal structure. Perhaps it was the result of a collision with a smaller body. It is likely that the Toutatis is two faced and stuck object.

There is an opinion: the strange shape of the asteroid was the result of the YORP effect, which explains how under the action of only one sunlight asteroid can start to rotate. Wind blowing on the propeller, sets it in motion, explains Dan Shears at the University of Colorado (USA), studying Toutatis for nearly two decades. The same thing happens when photons fall in rough body, forcing him to spin faster. Mr. Shears believe that at some point the asteroid has acquired such speed that began to throw material into space, resulting in one body turned into two. They both slowed down and was reunited, and then it all started again.

New data on the asteroid were presented at conference of the American geophysical Union.

Based on the materials of National Geographix.