According to a study conducted by scientists from Cornell University and published in the journal Geophysical Research Letters the Tunguska event which flattened hundreds of square miles of Russian forest was likely a comet striking the earth.
The finding is based on the appearance of noctilucent clouds in the thousands of miles away the next day. Noctilucent clouds form at an altitude of approximately 55 miles and are sometimes observed after shuttle launches.
"It's almost like putting together a 100-year-old murder mystery. The evidence is pretty strong that the Earth was hit by a comet in 1908," said study leader Professor Michael Kelley.
