The Roche limit only threatens objects held together by gravity, while solid objects held together by electromagnetic forces, such as rocks or pen caps, are unaffected.

“If you're just a solid object, the Roche limit is irrelevant to you. Okay? You're a solid object. You are not held together by the forces of gravity.”

Nuclear devices are a last-resort option for planetary defense, but kinetic impactors are the preferred method for deflecting asteroids.

“I mean yes I mean nuclear devices are a kind of Last Resort if something is really big and we don't have much time to react but in reality we would have probably decades to prepare and we would probably go with the kinetic impactor”