The Tunguska event was a large explosion, caused by an asteroid or comet, which occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, at about 07:14 KRAT (00:14 UT) on June 30 [O.S. June 17], 1908. The explosion occurred at an altitude of 5–10 kilometres (3–6 mi) at 60.886°N, 101.894°E. It is classified as an impact event even though the object is believed to have burst in the air rather than hit the surface. Different studies have yielded widely varying estimates of the impacting object's size, on the order of 60 m (200 ft) to 190 m (620 ft). It is the largest impact event on Earth in recorded history.