Nice! A sprite cluster briefly flashes into view above a thunderstorm seen from Duluth, Minn. last night. The storm was part of giant cell near Marquette, Mich. some 200 miles away! Details: 24mm lens, f/2.8, 15 sec exposure, ISO 3200. James Schaff
Had I not been so focused on observing a gas cloud 4,000 light years away I might have seen my first sprite last night. Sprites are massive electrical discharges that occur high above thunderstorms. They look like jellyfish tentacles. Unlike lightning, which at 10,000° F is as hot as the face of the sun, sprites are cool, more like the cold glow of a fluorescent light. Individual sprites in a cluster span between 33 to 328 feet (10 to 100 m) across and flash into view from 31 and 60 miles (19 and 37 km) high, far above the tops of thunderclouds in a layer of the atmosphere called the ionosphere, the same region that hosts the aurora.
Red sprite bursts by Scott McPartland
Sprites are only faintly visible with the naked eye from a dark sky, appear colorless and flash into view for a split second. Thanks to a camera’s greater sensitivity they glow red in time ...