The Biggest Explosion In History Is Still A Mystery

On June 30, 1908, a massive explosion ripped through the sky over the Tunguska region of Siberia, flattening trees nearly 31 miles around. The blast is thought to have been produced by a comet or asteroid hurtling through Earth's atmosphere, resulting in an explosion equal to 185 Hiroshima bombs as pressure and heat rapidly increased.
But, with no impact crater and little evidence of such an object ever found, scientists remain perplexed as to what truly caused the event in which 'the sky was split in two' - and a new study has failed to reach a conclusion.