Neat effect of the rotors striking all the dust creating static electricity and sparks: The Kopp-Etchells Effect
I have seen quite a lot of images and combat footage from Afghanistan, a lot of it is incredible it is just a shame about the reporters who so often talk utter rubbish. One of the funner ones was a chap who was standing near a US vehicle, the gunner was firing his .50 and suddenly the reporter started wailing and screaming 'I've been hit!' In actual fact it was simply a shell case which had bounced off his helmet, plonker. There was a great one yesterday, footage of some US soldiers (SF guys or possibly rangers I think, judging by some of their kit) during an attack; one of them with a very pleasant midwestern accent said the Taliban were engaging in a 'bit of douchebaggery' which I thought was both very apt and a very entertaining turn of phrase. Anyhow, those pics are amazing, the 'fairydust' affect is amazing and the lighting is great, I wonder how long he had to sit and wait for that.
In that case, dust. I have seen it happen with water from rain as well. All that friction intensifies the static charge. Good post.