Tunguska Blast is 100 years old today June 30, 2008Posted by
jcconwell in Asteroid, Astronomy. Tags: comet, meteor, Tunguska
On June 30th, 1908 a giant blast near the Podkamennaya Tunguska
river leveled some 500,000 acres of forest, over 2000 square
kilometers. The blast was originally estimated to be between 10
to 20 Megatons of TNT, 1000 times more powerful than the
Hiroshima bomb, about the size of the largest H bomb in the
world’s arsenals. Because of the remote location, the political
upheaval of the first world war and the Russian revolution, the
first expedition did not reach the area until 1927. A blast area
of radius 15miles, with felled trees pointing away from the
center of impact was found , but no crater. The lack of a crater
has lead to the theory that an airburst of either a comet or
meteor at an altitude of approximately 5 miles caused the
destruction. The exact nature of the body whether comet or
meteor is still a matter of debate. The excess amount of nickel
and iridium in trees, both common