Asteroid Day this year, 30th June 2019, is exactly 111 years after the Tunguska impact event in Siberia, which destroyed an area of pristine forest the size of Tokyo. With blasted and burnt tree trunks leveled and stripped bare over such a vast area, it is as though a large atomic bomb had been dropped on the forest.
The debate still goes on in the research literature, but a popular theory is that this impact was caused by a small comet fragment, in the region of 328 feet (100 meters) in diameter, that exploded at an altitude of around 5 miles (8 kilometers). Its immense downward momentum caused the resulting fireball to target the forest below, like a great blast of dragon breath. No crater was formed, and due to its remote location, it’s thought nobody was actually killed.