The meteor we all saw streaking across YouTube from Russian dashboard cameras was the largest in a century, a scientist who studied the event told Nature's Geoff Brumfiel.
That would make it the biggest rock to hit the Earth since 1908's Tunguska wiped out a big old patch of Siberia.
"It was a very, very powerful event," says Margaret Campbell-Brown, an astronomer at the University of Western Ontario in London, Canada, who has studied data from two infrasound stations near the impact site. Her calculations show that the meteoroid was approximately 15 metres across when it entered the atmosphere, and put its mass at around 40 tonnes.
The infrasound stations are owned by Comprehensive Test Ban Treaty Organization, and are designed to provide independent data on weapons tests. The Russian meteor was substantially more powerful than the North Korean nuclear weapons test this month.
Read the full story at The Atlantic.