Web edition: February 15, 2013
Mother Nature took earthlings by surprise by exploding a meteor in the skies over Russia Friday morning. The boom occurred just hours before a much larger object was scheduled to pass the planet uneventfully at a distance of about 27,000 kilometers.
The Russian meteor has no connection to the asteroid 2012 DA14, which will reach its closest point to Earth at 2:30 p.m. Eastern time.
"The fireball is not related in any way to 2012 DA14," says Paul Chodas, a planetary scientist with NASA's Near Earth Object Program in Pasadena, Calif. He says the meteor was about a quarter the size of DA14, which is 50 meters across.
Still, this unexpected meteor caused plenty of damage, with various sources reporting about 1,000 injuries. The meteor streaked through the atmosphere at supersonic speeds, creating a shock wave that shattered glass in a deafening boom once it reached the surface. The Russian space agency estimated its velocity in the atmosphere at 30 kilometers per second.
“This is the largest reported fireball since Tunguska,” says Chodas, referring to the famous 1908 meteor that downed trees over an 800-square-mile area in Siberia, more than 1,000 miles from today’s impact. The Tunguska meteor is estimated to have been about the size of 2012 DA14."It certainly reminds us what even a smaller asteroid is capable of," Chodas says. "This is Mother Nature shooting across the bow."