June 30, 2018
Today is the fourth annual International Asteroid Day.
This day is now recognized by the United Nations, and it marks a global opportunity to raise awareness of the threat of numerous rocks zooming through space.
Asteroid Day is held on the anniversary of the Tunguska explosion, when a small asteroid struck the Earth over Tunguska, Siberia on June 30, 1908. Recently, in a revised estimation, it is believed that the event released the energy equal to 3 to 5 megatons of TNT, devastating an area of forest about 800 square miles.