Infrasound Detection and the Chelyabinsk Meteor
“Statistically, something this size hits the Earth approximately once every 50 years (though nothing this size or larger has been observed to hit the Earth since 1908). This event was nearly ten times as energetic as the Sulawesi, Indonesia fireball of 2009.”
This article by Margaret Campbell-Brown, Associate Professor in the Department of Physics and Astronomy at the University of Western Ontario, details the the infrasound contribution to the determination of the Chelyabinsk impact. You can read the entire article via CTBTO in the link here.