This effect is caused by the rotor blades hitting dust particles – similar to the sparks generated when grinding metal Posted on 2022/03/11 by Carl Robitaille When there is a lot of sand in the air, helicopters can sometimes produce a halo effect resembling the glow of distant galaxies. This effect is caused by the rotor blades hitting dust particles – similar to the sparks generated when grinding metal pic.twitter.com/K2QyGYYsIP— Fermat's Library (@fermatslibrary) February 27, 2022