The Tunguska event of June 1908 is one of the most heavily referenced “unexplained” events of the 20th century. It comes up in both fiction and in reality all the time, and considering what probably caused it, you really can’t blame anyone for looking to it for inspiration.

Almost every respectable scientist has concluded that the gigantic explosion in remote Siberia – which flattened 80 million trees and smashed windows in towns 60 kilometers (37 miles) away – was caused by the air burst of a meteor. However, the lack of solid geological evidence for the original meteor, and a heavily delayed investigation into the incident, has convinced plenty that there must be a more outlandish explanation.

A group of Italian researchers have for at least a decade suggested that there was indeed a meteor blast, but one in which at least part of the space rock remained intact and smashed into Siberia. They go as far as to claim that they have found the original impact crater.

The team from the University of Bologna point to the rather picturesque Lake Cheko, which is located around 8 kilometers (about 5 miles) from the epicenter of the blast (as marked by the pattern of the flattened trees). Not only is this lake not marked on maps prior to the 1908 event, but it is also deeper than other lakes in the region.

Seismic surveys of its bed indicate that sediment has been accumulating there for not much longer than a century. They also appear to show a very dense object buried within the center of the lake, which could be the stony or iron remnants of the original meteor.

The team argue that two bodies entered the Earth’s atmosphere, either originally as part of the same object or as two long-segregated entities. One exploded in the air due to the extreme pressure building up at its front, causing the explosion we’ve all come to know and love. The second part smashed into the ground, forming Lake Cheko.

^{Photograph from a 1929 expedition near the Hushmo River. Wikimedia Commons; Public Domain}

“We have no positive proof this is an impact crater, but we were able to exclude some other hypotheses, and this led us to our conclusion,” Professor Giuseppe Longo, the research team leader, told BBC News in 2007.

As reported by the Siberian Times, researchers from the Russian Academy of Sciences have been doing a bit of investigating themselves, and they’ve now come to strongly dispute this theory. Using sediment cores taken from the base of the lake, they have dated them to be at least 280 years old, meaning it was there long before Tunguska occurred.

The research is yet to be published in an academic journal, but it’s worth pointing out that meteors do often explode in mid-air without leaving a sizable fragment afterwards.

[H/T: Siberian Times]