Scientists have warned that meteors like Chelyabinsk are more common than thought.
On February 15, 2013 the Chelyabinsk meteor, entered the Earth's atmosphere over Russia and the Near-Earth Object (NEO) had an estimated speed of about 18.6 km per second, which is nearly 60 times the speed of sound. The light emitted from the meteor is said to be brighter than the sun and eyewitnesses also reported that they felt intense heat radiate from the meteor.
The NEO's enormous velocity and low atmospheric entry angle made it explode in an air burst over Chelyabinsk Oblast, Russia, nearly at a height of 23.3 km (approximately 76,000 feet). The explosion of the meteor when it entered Earth's atmosphere generated a bright flash and produced many small fragmentary meteorites along with a powerful shockwave.
The NEO was undetected before it entered the atmosphere and its explosion created panic among local residents. Around 1,500 people were reportedly injured; however, all the injuries were due to indirect effects such as broken glass, which shattered due to the shockwave.
"It was amazing to see the damage done by an asteroid impact firsthand," said Peter Jenniskens, a meteor astronomer at NASA's Ames Research Center and the SETI Institute, and co-author of a study on the Chelyabinsk event that was detailed online on November 7 in the journal Science. "You could tell it really made a deep impression on people there."
Researchers believe that the Chelyabinsk meteor was a warning sign and such meteors are more common than thought earlier.
Recent research suggests that there is a risk from smaller NEOs that strike the Earth before they are detected and not just from the detected and bigger NEOs.
"The biggest hazard from asteroids right now is the city-busting airbursts, not the civilization-busting impacts from 1-kilometer-diameter objects that has so far been the target of most astronomical surveys," said Jay Melosh, an astronomer at Purdue University.
Astronomers indicate that telescopes can detect NEOs as small as three feet but some of them, such as the Chelyabinsk meteor, go undetected. More NEOs can hit the Earth but some astronomers believe that the damage may be minimal and may not cause global threat.
