photojojo:

These other-worldly coronas of light are a result of the Kopp Etchells Effect. &nbsp;
When the conditions are just right in the deserts of Afghanistan, sand in the air strikes&nbsp;titanium/nickel abrasion strips in the rotors of Chinook Helicopters.
Desert Halos: The Kopp Etchells Effect
Photo by&nbsp;U.S. Army/Sgt. Mike MacLeod, via The Atlantic In Focus
