Hi Rob,

Actually, impacts wouldn't kick up a lot of dust, although they would kick up some. The reason is that there is no atmosphere to be disturbed, and therefore no medium for the dust to be carried in, aside from the gasses produced directly by the impact itself. Most of the dust kicked up would follow a simple parabolic trajectory, and even for a relatively large impact, would settle back to the surface within a few minutes.

Looking for flashes of light, of course, is a lot of fun. When I was 13, I could have sworn that I saw a naked-eye impact. It was a very brief orange-white flash on the left side of Mare Serenitatis, which dissipated within a second or two. Got me very excited, but when none of the astronomy press reported anything about it, I assumed that my eyes had been playing tricks on me.

Cheers,

Nathan.