When certain helicopters in Afghanistan touch down on sandy ground, raising dust they cause mysterious arcs of light to loop and dance through the air.
It is believed to be Fractoluminescence – the emission of light from the fracture (rather than rubbing) of a crystal where the fracturing often occurs with rubbing.
In other words, the fracturing of the quartz sand is causing the illumination.
These photos are courtesy of Michael Yon and United States Forces personnel.
