Almost a century after a mysterious explosion in Russia flattened a huge swath of Siberian forest, scientists have found what they believe is a crater made by the cosmic object that made the blast. The crater was discovered under a lake near the Podkamennaya Tunguska River in western Siberia, where the cataclysm, known as the Tunguska event.

On June 30, 1908, a ball of fire exploded about 6 miles (10 kilometers) above the ground in the sparsely populated region, scientists say. The blast released 15 megatons of energy—about a thousand times that of the atomic bomb dropped on Hiroshima—and flattened 770 square miles (2,000 square kilometers) of forest.

Since then many teams of scientists have combed the site, but none was able to find any fragments of an object, like a rocky asteroid or a comet, that might have caused the event.

In their new study, a team of Italian scientists used acoustic imagery to investigate the bottom of Lake Cheko, about five miles (eight kilometers) north of the explosion’s suspected epicenter.

[nationalgeographic.com, Read More...]