Russian meteorite explosion was as powerful as 400,000 tonnes of TNT and appeared 30 times brighter than the sun, study reveals



U.S. physicist Mark Boslough said collisions from outer space could cause more damage than nuclear explosions

The scientist, at Sandia National Laboratories in New Mexico, believes experts underestimate the population of objects that can make air bursts

The rate of small space rocks entering the Earth's atmosphere is much higher than previously thought, he warns

Sandia researcher Mark Boslough shows the fine points of the 'fireball' that might be expected from an asteroid exploding in Earth's atmosphere, as indicated in a supercomputer simulation

A meteor that exploded over Russia was 30 times brighter than the sun, with the force of 40 Hiroshima atom bombs, said scientists.

Their analysis confirmed the meteor crash was the biggest in a century.



They also warned it was a wake-up call for humanity about the increased threat of space rocks smashing into the Earth.

The 62ft-wide missile exploded in a fireball above the city of Chelyabinsk on February 15, causing damage up to 50 miles away. At its fastest, it was travelling at more than 40,000mph.



According to experts, combining the recent Chelyabinsk crash with the 1908 Tunguska explosion over Siberia and the 1963 Bolide blast off the coast of South Africa, data suggests that the rate of small space rocks entering our atmosphere is actually much higher than previously thought.

Speaking at at the American Astronomical Society's 2013 Division for Planetary Sciences meeting, Mark Boslough, a physicist at Sandia National Laboratories in New Mexico, explored the implications of the Chelyabinsk airburst event, which happened on October 7 this year.



‘These three data points together suggest that maybe we have underestimated the population of smaller sized objects that can create air bursts,’ said Dr Boslough.



‘We think the airburst hazard is greater than previously thought,’ he added.

The 1963 Bolide blast was a 1.1-megaton explosion picked up by a global network of infrasound sensors, but not apparently seen by any observers.



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This space rock blew apart 18.5 miles above the city of Chelyabinsk, briefly outshining the sun and inflicting severe burns on a number of observers below. It was the largest object to hit the Earth since the Tunguska event of 1908, when an exploding comet or asteroid destroyed 2,000 square kilometres of Siberian forest

The explosion of a previously undetected asteroid about 25 miles from the Russian city of Chelyabinsk, led to widespread blast damage, Space.com reported.

According to the University of California, the space rock blew apart 18.5 miles above the city, briefly outshining the sun and inflicting severe burns on a number of observers below.



But it has also spurred a wealth of data helping scientists to gauge the object's size, angle of entry and other specifics, Dr Boslough said.

He estimates the explosive yield of the most recent space rock was at 400 to 500 kilotonnes, making it the most powerful event since Tunguska.

The impact site of the main mass of the Chelyabinsk meteorite in the ice of Lake Chebarkul

2000 EM26's flyby is almost exactly a year after a meteor unexpectedly exploded above Chelyabinsk, Russia, causing damage and injuring more than 1,000 people with falling glass

WHAT IS AN AIR BURST?

A naturally-occurring air burst arises from the explosion of incoming meteors, which explode in the air and not on the ground.

Examples include the Tunguska event, the Curuçá River event and the Chelyabinsk meteor event. The term also refers to the detonation of an explosive device such as a nuclear weapon in the air. The principal military advantage of an air burst over a ground burst is that the energy from the explosion is distributed more evenly over a wider area.

The Chelyabinsk meteor, which measured around 20 metres in diameter with a mass of 12,000 tonnes, exploded just 30km above the ground.

Fortunately, the meteor came in at an angle to spread its energy sideways, creating less damage on the ground.

Peter Brown, a physics professor at the University of Western Ontario in Canada, has collected over 500 videos of the event which injured around 1,500 people as glass windows shattered in the post-explosion shockwave.

Dr Boslough believes taking cover on the ground and staying away from windows is the best course of action in the event of another similar occurrence.

Writing in journal Acta Astronautica, he predicts the next destructive Near Earth Object (NEO) event will be an airburst and has suggested an outburst warning system should be used to deal with the threat.

Three data points suggest that scientists have underestimated the population of smaller sized objects (such as meteors) that can create air bursts. An illustration of an asteroid headed towards Earth is illustrated

U.S. government sensors also documented the Chelyabinsk event and released the data captured to the scientific community.



Commenting on another expert's concerns that an air burst could he misinterpreted as a preemptive attack from another country, Dr Boslough said he thought the worries were exaggerated before he watched a number of Chelyabinsk event videos.

'Say that this had happened on an overcast day, where nobody actually saw the streak across the sky. Then you see smoke, hear a large explosion and a lot of things that sound like artillery fire.

