Original URL: http://www.theregister.co.uk/2013/02/27/chelyabinsk_meteor_trajectory_reconstruction/

Colombian boffins reconstruct flight path of Russian meteor

Trajectory apparently began in near-Earth asteroid group Apollo

By Brid-Aine Parnell

Posted in Science, 27th February 2013 14:46 GMT

Astroboffins have figured out where the Chelaybinsk meteorite came from using the power of maths and videos shot by witnesses in Russia.

Jorge Zuluaga and Ignacio Ferrin of the University of Antioquia in Colombia have come up with a preliminary reconstruction of the orbit of the meteor, which smashed into the city in the Urals completely unexpectedly two weeks ago.

By combing through the witness videos and using trigonometry, the astronomers have determined that the meteorite came from the Apollo class of asteroids in our Solar System's space rock belt.

The Apollo asteroids are a bunch of near-Earth space rocks that regularly cross our world's orbit. The Apollos, named after the first of the group to be spotted - 1862 Apollo, which was first spotted in 1932 - have semi-major axes larger than the axis of Earth.

The boffinry team admits that the semimajor axis of the Chelyabinsk meteor and the inclination of its preliminary orbit are uncertain and that their calculations rested on the assumption that the reported hole in the ice sheet of Lake Cherbakul was definitely made by a fragment of the space rock, but said that "the rest of the orbital elements are well constrained in this preliminary reconstruction".

The meteorite, estimated to weigh about 10,000 tonnes, hit the Earth's atmosphere at a speed of at least 54,000kmph two weeks ago and then shattered around 30 to 50km above the ground. The shockwave of the space rock breaking into Earth's air space damaged buildings in the city of Chelyabinsk, blowing out windows and injuring hundreds.

The full sums for the reconstruction are available on arXiv.org (PDF). ®