tunguska

In Brief: At 7:17 AM on the morning of June 30, 1908, a mysterious explosion occurred in the skies over Siberia. It was caused by the impact and breakup of a large meteorite, at an altitude roughly six kilometers in the atmosphere. Realistic pictures of the even t are unavailable. However, Russian scientists collected eyewitness accounts of the event. I believe that we now know enough about large impacts to "decode" the subjective descriptions of the witnesses and …

…and more chance to have warn ing about impending impacts. For further information: Chyba, C., P. Thomas, and K. Zahnle 1993. "The 1908 Tunguska Explosion: Atmospheric Disruption of a Stony Asteroid". Nature 361, p. 40-44. (Calculation of size of the bolide.) Gallant, Roy A. 1994 "Journey to Tunguska". Sky and Telescope, June, 38-43. (Description of a modern journey to the site, with photographs.) Krinov, E. L. 1966 Giant Meteorites (London: Pergamon Press). (Description of the site and interviews with witnesses).