In 1908, thunderous blasts and blazing fires from the sky descended upon the desolate Tunguska territory of Siberia. The explosion knocked down an area of forest larger than London and was powerful enough to obliterate Manhattan. The mysterious nature of the event has prompted a wide array of speculation and investigation, including from those who suspected that aliens from outer space had been involved. In this deeply researched account of the Tunguska explosion and its legacy in Russian society, culture, and the environment, Andy Bruno recounts the intriguing history of the disaster and researchers' attempts to understand it. Taking readers inside the numerous expeditions and investigations that have long occupied scientists, he foregrounds the significance of mystery in environmental history. His engaging and accessible account shows how the explosion has shaped the treatment of the landscape, how uncertainty allowed unusual ideas to enter scientific conversations, and how cosmic disasters have influenced the past and might affect the future.