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The Chelyabinsk meteor (Russian: Челябинский метеорит, romanised: Chelyabinskiy meteorit) was a superbolide that entered Earth's atmosphere over the southern Ural region in Russia on 15 February 2013 at about 09:20 YEKT (03:20 UTC).

It was caused by an approximately 18-meter (60 ft), 9,100-tonne (10,000-short-ton) near-Earth asteroid that entered the atmosphere at a shallow 18‐degree angle with a speed relative to Earth of about 19.2 km/s (68,980 km/h; 42,860 mph). The light from the meteor was briefly brighter than the Sun (which is about −26.7 magnitude), visible as far as 100 kilometers (62 miles) away. The object exploded in a meteor air burst over Chelyabinsk Oblast, at a height of about 30 kilometres (18.6 miles). The explosion generated a bright flash, producing a hot cloud of dust and gas that penetrated to 26 kilometres (16 mi), and many surviving small fragmentary meteorites. Most of the object's energy was absorbed by the atmosphere, creating a large shock wave. The asteroid had a total kinetic energy before atmospheric impact equivalent to the blast yield of 400–500 kilotonnes of TNT (1.7–2.1 petajoules), estimated from infrasound and seismic measurements. This was approximately 30 times as much energy as that released by the atomic bomb detonated at Hiroshima. The object approached Earth undetected before its atmospheric entry, in part because its radiant (source direction) was close to the Sun. All of the injuries were due to indirect effects rather than the meteor itself, mainly from broken glass from windows that were blown in when the shock wave arrived, minutes after the superbolide's flash. The earlier-predicted and well-publicized close approach of a larger asteroid on the same day, the roughly 30 meters (100 feet) 367943 Duende, occurred about 16 hours later; the very different orbits of the two objects showed they were unrelated to each other.

During the Chelyabinsk meteoroid's traversal, there was a bright object trailing smoke, then an air burst (explosion) that caused a powerful blast wave. The last time a similar phenomenon was observed in the Chelyabinsk region was the Kunashak meteor shower of 1949, after which scientists recovered about 20 meteorites weighing more than 200 kg (440 lb) in total. The Chelyabinsk meteor is thought to be the biggest natural space object to enter Earth's atmosphere since the 1908 Tunguska event, and the only one confirmed to have resulted in many injuries, although a small number of panic-related injuries occurred during the Great Madrid Meteor Event of 10 February 1896. According to the Russian Academy of Sciences, the meteor then pushed through the atmosphere at a velocity of 15 km/s (33,550 mph) Video recordings show the radiant of the meteor (its apparent position of origin in the sky) above and to the left of the rising Sun. Early analysis of CCTV and dashcam video posted online indicated that the meteor approached from the southeast, and exploded about 40 km (25 mi) south of central Chelyabinsk above Korkino at a height of 23.3 kilometres (76,000 ft), with fragments continuing in the direction of Lake Chebarkul. The Russian Geographical Society said the passing of the meteor over Chelyabinsk caused three blasts of different energy. Additional scientific analysis of US military infrasound data was aided by an agreement reached with US authorities to allow its use by civilian scientists, implemented only about a month before the Chelyabinsk meteor event.

Based on its entry direction and speed of 19 kilometres per second (12 mi/s), the Chelyabinsk meteor apparently originated in the asteroid belt between Mars and Jupiter.

Less than 15 hours after the meteor impact, videos of the meteor and its aftermath had been viewed millions of times. On 27 March 2013, a broadcast episode of the science television series Nova titled "Meteor Strike" documented the Chelyabinsk meteor, including the significant contribution to meteoritic science made by the numerous videos of the airburst posted online by ordinary citizens.

Quick Facts

• The object exploded in a meteor air burst over Chelyabinsk Oblast, at a height of about 30 kilometres (18.6 miles).
• The light from the meteor was briefly brighter than the Sun (which is about −26.7 magnitude), visible as far as 100 kilometers (62 miles) away.
• The asteroid had a total kinetic energy before atmospheric impact equivalent to the blast yield of 400–500 kilotonnes of TNT (1.7–2.1 petajoules), estimated from infrasound and seismic measurements.
• Based on its entry direction and speed of 19 kilometres per second (12 mi/s), the Chelyabinsk meteor apparently originated in the asteroid belt between Mars and Jupiter.
• On 27 March 2013, a broadcast episode of the science television series Nova titled "Meteor Strike" documented the Chelyabinsk meteor, including the significant contribution to meteoritic science made by the numerous videos of the airburst posted online by ordinary citizens.

Source material: Wikipedia - "Chelyabinsk meteor". Adapted and summarized for DiscoverScroll. Original contributors are credited through the linked Wikipedia article. Read original on Wikipedia. CC BY-SA 4.0. Changes were made from the original.