I was driving from Burlington, VT to the Boston area last night (well early this morning I guess) and passed through Lebanon around 2:15 am. Somewhere between the VT/NH border and exit 19, there was some kind of bright flashing light coming from south of the highway. I thought it was lightning at first, but it kept repeating with a regular rhythm, at least 120bpm, so it was pretty clearly manmade. It was quite foggy out, which made the whole sky flash in rhythm with the light. Any locals know what that was?