Thirteen seconds after atmospheric entry, at a. The approximate effective diameter of the asteroid is estimated to be about 18 meters about Approximate total impact energy of the Chelyabinsk Fireball, in kilotons of TNT explosives the energy parameter usually quoted for a fireball , is kilotons. Note that these estimates of total energy, diameter and mass are very approximate. The Chelyabinsk event was an extraordinarily large fireball, the most energetic impact event recognized since the Tunguska blast in Russian Siberia.
The U. A similar calculation can be made from analysis of video records of the event; both methods yield similar results. This path through the atmosphere reinforces that the fireball was not associated with asteroid DA14, which made a very close flyby of Earth just over 16 hours later. This is known because the two objects approached the Earth from completely different directions and had entirely different orbits around the sun.
And, their compositions are dissimilar. The meteorite fragments emanating from the fireball are reportedly composed of silicate-rich ordinary chondrites, whereas the telescopic spectral data of asteroid DA14 suggest a carbon-dominated composition with abundant calcium- and aluminum-rich inclusions.
NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them, and plots their orbits to determine if any could be potentially hazardous to our planet.
PST, or p. EST on Feb. Not at all, Abell counters. Instead, he says these recent events are not due to the fact that Earth is passing through a swarm of undetected near Earth asteroids; rather these encounters are statistically random. Each day, he notes, hundreds of tons of meteorites fall on us all over the Earth, most which fall into the oceans. But as Abell points out, researchers now have a plethora of new atmospheric fireball and meteor detection methods at their disposal.
NASA and other U. Government agencies have better sensors that now help look at such high altitude events, says Abell. He notes that there are also more dash cams and security cameras and cell phone cameras; including cell phone apps, capable of easily filing reports of these bolides to a central office. We have a pretty good understanding of where 95 percent of the near-Earth asteroids one km in diameter and up actually are, says Abell. But, he says, surveys of near-Earth objects of meters or less are not even one percent complete.
The dazzling light was bright enough to cast moving shadows during the morning daylight in Chelyabinsk. Less than 20 seconds after its entry in the atmosphere, the meteoroid exploded and broke apart at about 23 km above the ground.
The energy released during the explosion was about 30 times as powerful as the atomic bomb dropped on Hiroshima in An event of this magnitude is expected to occur once every years on average. This is the most destructive meteoroid explosion event since the Tunguska event happened also over Russia in As this explosion occurred very close to a city, it was the only meteor event that was known to cause significant damage to the human world.
Damage caused by the meteorite explosion in Chelyabinsk Drama Theatre. The meteoroid had not been detected before atmospheric entry. It approached the Earth along a direction that remained within 15 degrees of the direction of the Sun.
Asteroid detection telescopes cannot scan regions of the sky this close to the Sun. Coincidently, another asteroid named DA14 was predicted to have a close encounter with the Earth, passing within 27, km of the Earth's surface just 16 hours after the fireball event. Yet, there is no connection between these two events as the two objects approached the Earth from completely different directions and had entirely different orbits about the Sun.
Based on videos of the Russian meteor, scientists reconstructed that the meteoroid should be a near Earth asteroid with its aphelion furthest distance from the Sun in the asteroid belt.
Comparison of the orbits of the Chelyabinsk impactor and asteroid DA14 showed that they were unrelated. A meteorite sample found by Ural Federal University scientists at Chebarkul lake. Similar explosion events did happen before. Brumfiel, G.
Russian meteor largest in a century. Nature Download citation. Published : 15 February Anyone you share the following link with will be able to read this content:. Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative. SN Applied Sciences Advanced search. Skip to main content Thank you for visiting nature. Download PDF. Subjects Astronomy and astrophysics Planetary science. This article has been updated. The meteor contrail seen over Chelyabinsk, Russia, on 15 February.
The object's explosion in the atmosphere is reported to have injured more than people. Credit: Chelyabinsk. Change history 15 February An earlier version of this article estimated the mass of the meteor at around 40 tonnes.
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