When Is an Aurora Not an Aurora? Explaining Mysterious Phenomena Called “Steve” and “Picket Fence”

A normal aurora (left) consists of glowing curtains of red, green and blue. An enhanced aurora (right) contains a thin, brighter layer which exhibits much more green, possibly caused by the same physical process that creates Steve and the picket fence. Because enhanced auroras are more common, UC Berkeley researchers plan to probe them first to determine what conditions in the upper atmosphere cause the phenomena. Credit: Vincent Ledvina, theauroraguy.com