O script é bastante claro sobre isso. Há uma falha no meio do meteoro. O plano deles é perfurá-lo, então, quando o meteoro estiver alinhado ao longo do seu eixo, detonar a bomba nuclear, dividindo o objeto em duas metades. Note que o tempo é fundamental.
Harry : From all of your intel, the deepest fault line is here. This is
my sweet spot. If I can get a clean hole in there, She'll blow in half....
Golden : ...and the two pieces will slide right past us. You cannot shatter it. Getting hit with 20 smaller asteroids is as bad as one big one. You have to drill, plant the nuke, lift off, and detonate -- all before the asteroid reaches this
position.(demonstrates position)
You have eight hours. Remember it. You must detonate by this point or the two halves will hit us.