Researchers have said that the meteorite that rocked Russia last year could have been sent on the collision course with Earth after it crashed into another asteroid as long as 290 million years ago.
The scientists believe that the parent asteroid, from which the Chelyabinsk meteor broke off, crashed into another asteroid in space at anywhere from 1,440 - 5,400 km/h.
According to the scientists, the second asteroid was at least 150m in diameter, and the crash sent the final 20m wide meteor in Earth's direction.
Lead researcher Shin Ozawa, of Japan's University of Tohoku, and his team discovered a mineral called jadeite in glass-like veins inside the samples of the Russia meteor which could only be produced under massive pressure and heat, like an impact with another asteroid.
The results have been published in the journal Scientific Reports.