The Tunguska Event: On June 30, 1908, a massive explosion occurred above the Tunguska region of Siberia. Witnesses saw a blinding blue light that turned red before a blast flattened 800 square miles of forest. The explosion was so powerful it was recorded as far away as London, yet no crater was ever found. Scientists believe it was an asteroid or comet that exploded in midair, but no debris has ever been confirmed. Over a century later, the Tunguska Event is still one of Earth’s greatest unsolv