On Tue, 1 Nov 2011 18:42:31 -0700 (PDT), Brad Guth
wrote:

Any direct hit or glancing blow to the moon could be extremely
problematic for us, especially if it happened on the nearside.

No, it wouldn't. No debris would be large enough to reach the Earth's
surface. At most, we'd see a meteor shower, and it wouldn't be dense
enough to be much of a threat to our satellites.

Nothing problematic at all. But it's academic, since we know the
elements, and we therefore know that it isn't going to hit the Moon.