The Tunguska event was an enormously powerful explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, on June 30, 1908. The explosion, having the epicentre: 60.886°N, 101.894°E; is believed to have been caused by the air burst of a small asteroid or comet at an altitude of 5 to 10 kilometres (3 to 6 miles) above Earth's surface.
Different studies have yielded widely varying estimates of the object's size, on the order of 60m (200ft) to 190m (620ft). It is the largest impact event on or near Earth in recorded history.
The number of scholarly publications on the problem of the Tunguska explosion since 1908 may be estimated at about 1,000 (mainly in Russian). Many scientists have participated in Tunguska studies, the best-known of them being Leonid Kulik, Yevgeny Krinov, Kirill Florensky, Nikolai Vladimirovich Vasiliev, and Wilhelm Fast.
In 2013, a team of researchers led by Victor Kvasnytsya of the National Academy of Sciences of Ukraine published analysis results of micro-samples from a peat bog near the blast epicenter showing fragments possibly of meteoric origin.
The Tunguska explosion knocked down an estimated of 80 million trees over an area covering 2,150 square kilometres (830 sq. mi.) and it is estimated that the shock wave from the blast would have measured 5.0 on the Richter scale, explosion capable of destroying a large metropolitan area. This catastrophic possibility, helped to spark the discussion on the importance of creating asteroid deflection strategies.
