On june 30, 1908
A small asteroid of approximately 200 feet ( 60 meters )
In diameter exploded at an altitude of 5 miles ( 8 kilometers )
over the remote region of tunguska in siberia
The explosive energy from the meteor was so great that half a million acres
of siberian forest were devastated and some tree were knocked over at distances as far as 25 miles ( 40 kilometers ) away