FIREBALL UPDATE: 300 tons of TNT. That's the kinetic energy of the meteoritic fireball sighted June 7th in Norway, according to Prof. Peter Brown of the University of Western Ontario. Brown's doctoral student, Wayne Edwards, arrived at this figure by analyzing infrasound and seismic data. Early reports of a Hiroshima-like event (12,000+ tons of TNT) were exaggerated.
"An object like this hits Earth about once a month," notes Bill Cooke of the Marshall Space Flight Center. For comparison, "the Norwegian event was similar to, but somewhat less energetic than the Park Forest meteorite impact of 2003."
Meteorites from the Norwegian fireball probably did reach the ground. One candidate landing site, however, is viewed with skepticism by experts. Where are the space rocks? The hunt continues.