(Friday, Feb. 15) — Using sensors developed in the 1950s, which can pick up low-frequency sound waves that humans can’t hear, scientists estimate that the explosion of a meteor over the town of Chelyabinsk in Russia was the largest of its kind in more than a century.
The explosion caused about 1,200 injuries, including 200 children, reports said.
The detectors for sub-audible sounds, known as “infrasound,” were originally developed to determine whether Cold War enemies of the US were setting off nuclear bombs. The nukes had a certain vibration pattern in the infrasonic spectrum, which could be detected around the world. Since the end of the Cold War, these sensors have been used mostly to study and predict avalanches (PDF).
But Friday, they tracked the meteor. NASA’s Near Earth Object Program analyzed the infrasound data and shared a few facts about the meteor that hit Siberia on its website:
The Russia meteor is the largest reported since 1908, when a meteor hit Tunguska, Siberia. The meteor entered the atmosphere at about 40,000 mph (18 kilometers per second). The impact time was 7:20:26 p.m. PST, or 10:20:26 p.m. EST on Feb. 14 (3:20:26 UTC on Feb. 15), and the energy released by the impact was in the hundreds of kilotons.
Scientists put a conservative estimate on the energy released by the explosion at about 300,000 tons of TNT, about 20 times the energy of the explosion that resulted from the atomic bomb that destroyed Hiroshima during World War II. The atomic bomb explosion had the equivalent of about 15,000 tons of TNT.
NASA scientists said the meteor was unrelated to asteroid 2012 DA14, which came from a different direction and missed Earth by about 17,000 miles Friday, the BBC reported. This is closer than the geosynchronous orbits of most telecommunications satellites.
“There is no relation there,” the New York Times quoted Paul Chodas, a scientist with the Near Earth Object Program, as saying. “It seems like we’re in a cosmic shooting gallery here. … Pure coincidence.”
