Great work on this. It's easy to use and fun to play with. I spent more time than I'd care to admit zooming in, panning around, and looking at all of the different impact sites.

I also liked your write-up of the project: http://www.roadtolarissa.com/meteor-map/

(The only small, minor, nitpicky thing I noticed was hovering over a new impact site displayed the old one for a split second. You probably already knew that though :)