Astronomers trace the origin of a meteor that injured about 1,000 people after breaking up over central Russia earlier this month.
Using the footage and the location of an impact into Lake Chebarkul, Jorge Zuluaga and Ignacio Ferrin, from the University of Antioquia in Medellin were able to use simple trigonometry to calculate the height, speed and position of the rock as it fell to Earth.
To reconstruct the meteor's original orbit around the Sun, they used six different properties of its trajectory through Earth's atmosphere. Most of these are related to the point at which the meteor becomes bright enough to cast a noticeable shadow in the videos.
The Chelyabinsk meteor (labelled ChM) appears to have been on elliptical orbit around the Sun before it collided with Earth. The researchers then plugged their figures into astronomy software developed by the US Naval Observatory.
The results suggest the meteor belongs to a well known family of space rocks - known as the Apollo asteroids - that cross Earth's orbit.
Of about 9,700 near-Earth asteroids discovered so far, about 5,200 are thought to be Apollos. Asteroids are divided into different groups such as Apollo, Aten, or Amor, based on the type of orbit they have.
Dr. Stephen Lowry, from the University of Kent, said the team had done well to publish so quickly. "It certainly looks like it was a member of the Apollo class of asteroids," he told said. "Its elliptical, low inclination orbit, indicates a solar system origin, most likely from the asteroid belt between Mars and Jupiter. Dr. Lowry added: "Perhaps with more data, we can determine roughly where in the asteroid belt it come from."