Source from : Dawn.Com
MOSCOW: Divers scoured the bottom of a Russian lake on Saturday for fragments 
of a meteorite that plunged to Earth in a blinding fireball whose shockwaves 
injured 1,200 people and damaged thousands of homes.
The 10-tonnes meteor streaked across the sky in the Urals region on Friday morning just
as the world braced for a close encounter with a large asteroid that left some Russian officials
calling for the creation of a global system of space object defence.
The unpredicted meteor strike brought traffic to a halt in the industrial city of Chelyabinsk
as residents poured out on the streets to watch the light show before hovering for safety
as a sonic boom shattered glass and set off car alarms. The shattered glass injured most
of the people.
“We have a special team working… that is now assessing the seismic stability of buildings,”
Emergencies Minister Vladimir Puchkov told residents as he inspected the damage in the
central Russian city.
“We will be especially careful about switching the gas back on,” he said in televised remarks.
A fragment of the meteor – called a meteorite once it hits the ground – was believed to
have plunged into the Chelyabinsk region’s frozen Lake Chebarkul.
“A group of six divers will inspect the waters for the presence of pieces of a meteorite,” an
emergencies ministry spokeswoman told Russian news agencies moments before the start
of the operation.
But Puchkov stressed that no fragments had been discovered anywhere in the region so far
despite some 20,000 rescuers and recovery workers being dispatched to the region on Friday.
The meteor explosion appears to be one of the most stunning cosmic events above Russia
since the 1908 Tunguska Event in which a massive blast most scientists blame on an asteroid
or a comet ripped through Siberia.
Scientists at the US space agency Nasa estimated that the amount of energy released from
impact with the atmosphere was about 30 times greater than the force of the nuclear bomb
dropped on the Japanese city of Hiroshima during World War II.
“We would expect an event of this magnitude to occur once every 100 years on average,”
said Paul Chodas of Nasa’s Near-Earth Object Program Office.
“When you have a fireball of this size we would expect a large number of meteorites to reach
the surface and in this case there were probably some large ones,” he said in a statement
published on the NASA website.
The drama in Russia developed just hours before an asteroid – a space object similar to
a tiny planet orbiting the sun – whizzed safely past Earth at the unprecedented distance
of 27,000 kilometers.
That put it closer to the ground then some distant satellites and sent off alarm bells ringing
 in some Russian circles about this being the time for joint global action on the space
safety front.
“Instead of fighting on Earth, people should be creating a joint system of asteroid defence,” the
Russian parliament’s foreign affairs committee chief Alexei Pushkov wrote on his Twitter
account late Friday.
“Instead of creating a (military) European space defence system, the United States should join
us and China in creating the AADS – the Anti-Asteroid Defence System,” the close ally of
President Vladimir Putin wrote.
The US space agency said the 2012 DA 14 asteroid’s passing was “the closest-ever predicted
approach to Earth for an object this large.”
NASA estimates that a smallish asteroid such as the 2012 DA 14 flies close to Earth every
40 years on average while only hitting the planet once every 1,200 years.
Astronomers have detected some 9,500 celestial bodies of various sizes that pass near Earth.