Itoyama Impact Event

The Itoyama Impact Event (糸山彗星の影響大災) was a impact event that occurred on Kita-Itoyama a small town in Itoyama, Yamazaki Prefecture, Nakama on night of 26 August 2013. The comet fragment collided with ground in populated town of Kita-Itoyama causing crater which later formed second Itoyama Lake in the area.

The Itoyama Impact Event is the largest physical collision impact event on Earth in recorded history and second largest after Tunguska event in Russia. Studies have yielded different estimates of the meteoroid's size, on the order of 40-60m, which came from fragment of comet.

It is estimated that the Itoyama Impact destroyed all 3km wide impact site and damaged total 5km from impact site causing the total destruction of Kita-Itoyama town and knocked down the forest nearby, and that the shock wave from the blast would have measured 6.5 on the Richter magnitude scale.