International Asteroid Day is a United Nations-recognized day observed each year at the international level during the anniversary of the Tunguska impact over Siberia, Russian Federation. The goal of International Asteroid Day is to raise public awareness about the asteroid impact hazards.

The Tunguska explosion of June 30, 1908 knocked down some 80 million trees over an area of 2,150 square kilometres (830 sq mi); the shock wave from the blast would have measured about 5.0 on the Richter scale.