Could be useful for blowing up an incoming asteroid. We're currently stuck in a dilemma where if the rock is small enough for a missile to actually wipe it out, it won't be dangerous enough to merit nuking in the first place. If we had a reliable and lightweight bomb that could take out a rock the size of Ceres, we would have a much better chance of defending our planet. Of course we would still have to refrain from annihilating ourselves.
