Helicopters flying at Mars may glow at dusk

The whirling blades on drones flying above Mars may cause tiny electric currents to flow in the Martian atmosphere, according to a NASA study. These currents, if large enough, might cause the air surrounding the craft to glow. This process occurs naturally at much larger scales on Earth as a corona or electrical glow sometimes seen on aircraft and ships in electrical storms known as Saint Elmo’s Fire.