Kiloton Explosion News Today

>> reporter: they know because of that boom. a 4 kiloton explosion. >> it shook a lot of houses and buildings on the ground. >> reporter: nasa is already working on the armageddon scenario. developing a small probe to ram asteroids and knock them off course. theyve even tested it successfully. all thats left of this one are tiny rocks no bigger than a baseball. >> but the men in black are on it? >> theyll be on it. >> reporter: david wright, abc news, pasadena. >> pretty amazing stuff. >> every ...