What caused a mysterious atmospheric explosion in Siberia in 1908?

Fire erupted in the morning skies over Siberia on June 30, 1908, as an atmospheric explosion occurred that remains unmatched by any similar event in modern history.That day, at approximately 7:15 a.m. local time, observers in Siberia's remote Tunguska region became witnesses to the entry of a brilliant fireball into Earth's atmosphere, trailing smoke across the dawn sky and culminating in a flash brighter than the sun itself. Within seconds, the explosion and resulting shock waves that followed