At the beginning of the 20th century, an asteroid the size of the White House was moving past Earth on its way to nowhere in particular. But as it had done for billions of years, with a billion other space rocks, our earth reached out and began pulling it toward us. Best guesses put that asteroid at between 30 and 50 meters across. If you had to walk all the way around it it would have taken you about eight minutes. For months, it continued toward us, gaining speed. By the time it hit our atmospherem it was doing at least 40,000 kilometers per hour… but probably a lot more. At that speed and size, it pierced our atmosphere. It was moving so fast that the air became an impenetrable wall. The massive meteor smashed into this wall of air and exploded like a hydrogen bomb. Imagine what that would have looked like from the ground. The debris cloud from the Tunguska event eventually destroyed an area over 2,000 square kilometers of forest. That’s an area as large as the City of London. It’s estimated that an event as large as Tunguska happens roughly every 500 years It WILL happen again.