St. Elmo's fire

St. Elmo's fire—also called witchfire or witch's fire—is a weather phenomenon in which luminous plasma is created by a corona discharge from a rod-like object such as a mast, spire, chimney, or animal horn in an atmospheric electric field. It has also been observed on the leading edges of airplanes, as in the case of British Airways Flight 009 and by US air force pilots.