The NY Times reports on what has been learned about the Chelyabinsk meteor, and the meteoroid that created it, in studies since the event: In Asteroid’s Aftermath, a Sigh of Relief : A Clearer View of the Space Bullet That Grazed Russia – NYTimes.com.

The report includes a video report on the event and on how non-professionals have participated in helping to refine the estimate of the orbit of the meteoroid.

Data from infrasound detectors around the world has helped in estimating the energy released in the fireball

the Canadian team has calculated that the energy released in the Chelyabinsk explosion was the equivalent of about 440 kilotons of TNT, or about 30 times the power of the Hiroshima bomb.

That calculation was made with the help of data from a network of acoustic sensors set up to monitor compliance with the treaty to ban nuclear weapons testing. There are about 45 of the sensors worldwide, detecting so-called infrasound at frequencies well below the range of human hearing.