I can't currently find a link, but I've seen speculation that nuclear explosions on the moon could serve to eject some of the moon's mass. Even a small change w

I can't currently find a link, but I've seen speculation that nuclear explosions on the moon could serve to eject some of the moon's mass. Even a small change would necessarily change the moon's orbit very slightly – and over enough time, the position of Earth-moon system would be quite different from what it would have otherwise been. (This was proposed as a way to move the Earth out of the path of an approaching body, given enough warning, without actually having to reach the much-further-away approaching body, and alter its path.)