The extremes of Earth's Late Heavy Bombardment
Monday, September 29, 2014 - 07:20
in Earth & Climate
On June 30, 1908 a bolide streaked across the sky in the region near the Podkamennaya Tunguska River in Russia. When it exploded, the airburst leveled more than 2,000 square kilometers of trees. It is now known as the Tunguska event. This particular region of Russia is extremely remote so the damage was limited to trees and other local flora and fauna. But the impact is estimated to have been on the order of 10 -15 megatons. If it had occurred over a major city, the bolide would have destroyed it as surely as dropping a modern nuclear weapon. A similar sized event occurred in Arizona 40,000 years ago, and produced a crater a kilometer wide.