On June 30, 1908, a small asteroid of approximately 200 feet (60 m) in diameter exploded at an altitude of 5 miles (8Km) 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 Km) away.