Free Astronomy Magazine September-October 2019

P hotographs taken during the first expeditions of Leonid Kulik, showing glimpses of the devastation of the Siberian taiga, produced by the Tunguska event. The few trees left standing were called “telegraph poles.” To fully evaluate the new reports, however, it is nec- essary to go back over what happened in Central Siberia in the now-distant June 30, 1908. At 7:15 local time, in the sky above a plateau bathed by the river Podkamennaya Tunguska, in an almost inac- cessible and uninhabited territory, a fireball ap- pears that some witnesses described as red, bigger and brighter than the Sun, and accompanied by a trail of dust, thunder, and a terrifying final explo- sion. Houses trembled even at great distances from the explosion site, a pressure wave went around the Earth twice and, in the following nights, an extraor- dinary brightness of the sky was noticed both in all of Russia and in northern Europe. In England, in the night between June 30 and July 1 st , the sky did not become dark, and in London you could read the newspaper at midnight. In Glasgow, Scotland, the night sky was so bright that only first and second magnitude stars were visible. Microbarographs of the Royal Meteorological Society recorded sharp