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Russian scientists report that eyewitnesses and seismic stations in the Irkutsk region of Siberia suggest an impact occurred in the area last Thursday. Eyewitnesses reported the fall of an object - Bodaibo residents saying they saw a very large, luminous body, which looked like a huge boulder, fall from the sky. Local hunters are also reporting a crater surrounded by burnt forest.
Vladimir Polyakov, of the Institute of Solar and Terrestrial Physics in Moscow, said: “Specialists have no doubt that it is a meteorite that fell into the taiga on Thursday.” He also said that more than 100 people had witnessed the fall. The event was also detected by geophones monitoring earthquakes. Kirill Levi, vice-director of the Earth Crust Institute in Siberia, said: "The seismic monitoring station located near the event site recorded the moment of impact recording seismic waves comparable to a middle-power earthquake."
Currently Russian scientists are requesting support to mount an expedition to the remote area to confirm whether an impact has occurred and of what magnitude.
A significant impact last occurred in Siberia at Tunguska in 1908 and destroyed 2000 square km of forest. In this event a weak asteroid or comet fragment is thought to have detonated before colliding with the ground and thus did not form a crater - the damage was caused by the airblast. Reports of a seismic disturbance, however, suggest that if the event that occurred on Thursday is an impact it may have formed a crater.
The fall of the large Sikhote Alin iron meteorite in 1947 in Russia did produce impact craters as steep sided pits in soft soil as it hit the ground at a speed of around 1 km per second. One 13 kg fragment from this meteorite even split a sizeable cedar tree in two.
If eyewitness accounts are accurate, then an impact of a strong asteroid fragment larger than the Sikhote Alin meteorite may well have occurred in Siberia last Thursday. This would be an event of significant scientific interest and could provide much information on the nature of these smaller, more frequent impacts. NEO scientists are, therefore, eager to confirm whether Siberia has again been ground-zero for a collision.
Impacts that produce small craters, although more frequent at perhaps every few hundred years, represent a much smaller hazard than the collision of km-sized asteroids with the Earth since they have only local effects. Current efforts in finding and tracking Near Earth Objects are, therefore, focusing on those larger than 1 km that collide with the Earth every few hundred thousand years but are capable of changing the global environment.
More info: BBC Online Article
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