What Is International Asteroid Day? International Asteroid Day is a global event dedicated to educating the public about asteroids, their impact on Earth, and the ways we can protect our planet from potential asteroid threats. It serves as a reminder of the importance of vigilance and scientific advancement in monitoring the skies. Why Is June 30 an Asteroid Day? June 30th was chosen to mark International Asteroid Day because it commemorates the Tunguska event, the most significant asteroid impact in recent history, which devastated over 2,000 square kilometers of forest in Siberia on this day in 1908. On this day in 1908, a massive explosion occurred in Siberia, believed to be caused by an asteroid or comet exploding in the atmosphere. This event released the energy equivalent of up to 15 million tons of TNT, flattening around 2,000 square kilometers of forest and knocking down 80 million trees. Despite occurring in a remote area, the explosion had global atmospheric eff...