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What are lightning sprites?

A red, glowing structure in the sky, with an intricate, jellyfish-like shape, domed top with streamers hanging down.

View at EarthSky Community Photos. | Stephen Hummel, who works at McDonald Observatory in West Texas, captured this fleeting lightning sprite – aka a red sprite – on July 2, 2020. McDonald Observatory is spearheading a Dark Skies Initiative in its region. Stephen commented, “Dark skies help you see faint objects like sprites.” Thank you, Stephen!

Did you know that lightning sprites – like the one captured in the image above – exist above some thunderstorms? Sprites aren’t terribly well known, except to meteorologists, nature photographers and others who study the skies. They aren’t especially rare, but they’re fleeting. They’re not easy to capture on film. Lightning sprites are electrical discharges high in Earth’s atmosphere. They’re associated with thunderstorms, but they’re not born in the same clouds that send us rain. Thunderstorms – in fact all earthly weather – happen in the layer of Earth’s atmosphere called the troposphere, which extends from Earth’s surface to about 4 to 12 miles (about 6 to 19 km) up. Lightning sprites – also known as red sprites – happen in Earth’s mesosphere, up to 50 miles (80 km) high in the sky.

So when you’re standing on Earth’s surface and you spot one, it appears relatively small, even though, in fact, sprites can be some 30 miles (50 km) across. As Matthew Cappucci of the Washington Post’s Capital Weather Gang said in an article about lightning sprites last year:

Imagine one electrical discharge spanning the distance from Baltimore to Washington, D.C.

Cappucci also commented:

Although sprites are poorly understood, atmospheric electrodynamicists have figured out the basics behind their formation. Sprites are often triggered by a strong, positive bolt of ordinary lightning near the ground. They’re thought to be a balancing mechanism that the atmosphere uses to dispense charges vertically. It’s a quick process that takes less than a tenth of a second.

That’s what makes hunting for sprites so tough. Blink and you’ll miss them.

The fleeting aspect of lightning sprites probably explains why – when people first see photos of them – they’re surprised that such a strange-looking weather phenomenon even exists.

Also, it hasn’t been that many years since lightning sprites were confirmed. In the 20th century, pilots spoke of “flashes above thunderstorms.” Lightning sprites as we know them today weren’t captured and their intricate structure didn’t begin to be recorded on film until as late as 1989, when experimental physicist John R. Winckler (1916-2001) happened to capture one while testing a low-light television camera.

Today, people around the world routinely capture photos of lightning sprites. You’ll find many photos of them in this gallery from SpaceWeather.com.

To photograph a sprite, you need a dark sky and a clear view toward a distant thunderstorm. The sky needs to be dark, because you’ll be taking long exposures; too much stray light in your sky will wash out your photo and make capturing sprites impossible. One of the most successful sprite photographers in the U.S., and likely in the world, is Paul M. Smith. He captured the sprite below in June 2020. You can follow him on Twitter: @PaulMSmithPhoto. Or find him on YouTube.

Want more photos of lightning sprites? Try these:

Lightning sprites over the Andes in early 2020, from Yuri Beletsky

Lightning sprites over Oklahoma in 2018, from Paul Smith

Captures of elusive red sprites from the International Space Station

Bottom line: Lightning sprites, or red sprites, often occurring in tandem with lightning, are short-lived electrical discharges that flash high above thunderstorms in the mesosphere layer of the atmosphere.

Deborah Byrd

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