Tunguska - the fire in the sky

No one can dispute the occurrence, but how it happened is the subject of continuing, and often heated, controversy. Despite the best efforts of science, every acceptable “explanation” leaves inescapable facts still shouting for attention.The event began at about 7:15 on the morning of June 30, 1908 in a remote region of central Siberia near the Stony Tunguska River. A blue-white fireball—brighter than the Sun, some said—raced across the sky, then exploded with the force of a 10- to 15- megaton hydrogen bomb.The explosion felled some 60 million trees across an area of 2000 square kilometers. Yet some trees near the blast center were not burnt and a ring of burnt trees circling the epicenter was left standing. The thunderous sounds were accompanied by a shock wave that knocked people off their feet and broke windows hundreds of kilometers away.The explosion registered on seismic stations across Europe and Asia, and as far away as Britain meteorologists registered fluctuations in atmospheric pressure. The resulting pulse of air pressure circled the Earth twice, and astronomers observed for several nights afterwards a glowing red haze in the upper atmosphere, though they were not aware of the cause at the time.

Curiously, reports of an unusually bright night sky began the night before the Tunguska event and continued for several days afterwards.For the next few weeks, reports suggest that the night skies were aglow to such an extent that one could read in their light. Both the Smithsonian Astrophysical Observatory and the Mount Wilson Observatory reported a decrease in atmospheric transparency persisting for several months.What, then, was experienced by the witnesses to the event: Accounts gathered by the Russian mineralogist Leonid Kulik, in his 1930 expedition to the site of the explosion are consistent enough on many details to be considered generally reliable.