The June 30, 1908 Tunguska blast remains an unexplained mystery. Universe Today reports Astronomycast responded to requests by devoting episode 243 to the Tunguska event. The speculations are varied as to what happened in Siberia, over a hundred yeas ago. Explanations include the reasonable such as an asteroid or comet to Tesla test firing an energy weapon. Regardless, a fireball split the sky in the early daylight hours with sufficient force to throw people off their feet to land yards away at a distance of forty miles! Victims experienced also intense heat from blast that flattened over 60,000,000 trees in a 200 sq mile area. Astronomycast Episode 243 is well done, and Tunguska, a natural science phenomenon! Please listen to the hosts who provide recent evidence. A previous post on the Tunguska blast can be read here. It's very interesting stuff!