nothing to do with ben aflac or drills. joining us is after the ro physicist of the american museum of natural history and welcome to the universe, a pocket-size tour, neil's, pleasure to see you as always, can you explain what this mission is trying to do? and why? >> well, you have to sort of know the structure of the solar system. we have mercury, venus, earth, mars and there is a gap before you get to jupiter. in that gap is countless asteroids. most of them are. a sub set have a wayward orbit that brings them close to the orbit of the earth. in some cases they cross the orbit of the earth. 100% of these can be considered potentially hazardous. this targeted asteroid is a binary as a moon and we know precisely the orbit of that moon