At about 9:20 a.m. local time (12:20 a.m. EST) Friday, February 15, 2013, a space rock nearly 50 feet (15 meters) in diameter entered Earth’s atmosphere and erupted over the Urals region in Russia. The “tiny asteroid,” as Paul Chodas, research scientist in the Near-Earth Object Program Office at NASA’s Jet Propulsion Laboratory in Pasadena, California, referred to it, weighed some 7,000 metric tons and penetrated the atmosphere at some 40,265 mph (18 kilometers per second).
According to Bill Cooke, lead for the Meteoroid Environments Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, the asteroid streaked through Earth’s atmosphere for approximately 30 seconds before it broke up 12 to 15 miles (19 to 24 km) above the surface. The resulting airburst released 300 to 500 kilotons of energy in a shock wave that quickly reached the ground.
For videos of the event, see "Meteor explodes over central Russia
According to Russia's Interior Ministry, most of the damage from the shock wave was reported in six locations: Yemanzhelinsk, Etkul, Lithuania, Korkino, Yuzhnouralsk, and Chelyabinsk. The blast damaged buildings and shattered windows. The ministry told the state-run RIA Novosti news agency that about 1,000 people had been hurt, including more than 200 children. The deputy governor of the Chelyabinsk Region, Igor Murog, told a meeting with President Vladimir Putin and Emergency Minister Vladimir Puchkov on Friday afternoon local time that 514 people have applied for medical aid, including 82 children. Two of the injured are in "grave" state. According to Murog, the flow of those applying for medical aid has stopped.
Although this explosion was the largest one since the Tunguska event over Siberia in 1908, Earth regularly comes into contact with such debris. "Earth intercepts about 80 tons of meteoritic material per day," Cooke said in a teleconference. Chodas added that a basketball-sized object hits Earth on average once per day and a car-sized one every month or two.
NASA is the worldwide leader in tracking large asteroids. The agency's Near-Earth Object Program has found more than 95 percent of large near-Earth objects (more than 0.67 mile [1km] in diameter). The tiny asteroid that broke up over Russia could not have been detected through this program because of its size. The object also came out of the dayside of the planet, according to scientists.
This asteroid is unrelated to the other event February 15, when the much larger asteroid 2012 DA14
made a safe — and predicted — flyby of Earth