The meteors were unusually big, between 6 and 10 feet in diameter. The first one created an explosive pressure wave with as much energy as 2,000 to 3,000 tons of TNT, according to Los Alamos researchers. Had anyone seen the April 23 event, they would have seen quite a show. Each year, listening stations at the lab record an average of 10 meteors 6 feet in diameter or greater. Those that appear as huge fireballs in the sky, like the April and August specimens, are known as bolides.
Bolides make dazzling displays dozens of miles above the planet.
Fortunately, most explode into thousands of pieces or burn up entirely before they reach the surface. If these two survived, they probably smacked into the ocean, well away from populated regions, the scientists said. An extremely large one blasted the huge Meteor Crater in Arizona. The unaided human ear cannot detect the low frequency pressure waves when at a great distance. But specialized microphones at four Los Alamos monitoring stations in the United States can both detect the infrasonic waves and help plot their locations.