The Tunguska Event: A Century Later, It’s Still Mysterious

One hundred years ago today, a fireball streaked across the morning sky over Siberia and exploded, flattening the forest across an area of 830 square miles. The cause of the Tunguska Event, named for the nearby Tunguska River, has been a source of speculation ever since, with theories ranging from the absurd (space aliens!) to the most plausible: a disintegrating meteor exploding in the atmosphere. But a century after the event scientists still don't have enough evidence to conclusively say what happened.