But even if Spaceguard does succeed, another problem remains smaller asteroids, of the size believed to have caused a huge explosion above Tunguska, in Russia, in 1908.
Siberia time in the morning in June of the year 1908 high in the sky above the Forest in the remote wilderness of Tunguska Siberia heard an explosion that laid flat more than 800 square miles of the forest with all the trees pointing away from the center of the blast with most all the trees laying on their side.