A flash of lightning, and then—something else. High above a storm, a crimson figure blinks in and out of existence. If you see it, you are a lucky witness of a sprite, one of the least-understood electrical phenomena in Earth’s upper atmosphere.
Sprites occur at some 50 miles (80 kilometers) altitude, high above thunderstorms. They appear moments after a lightning strike – a sudden reddish flash that can take a range of shapes, often combining diffuse plumes and bright, spiny tendrils. Some sprites tend to dance over the storms, turning on and off one after another. Many questions about how and why they form remain unanswered. Sprites are the most frequently observed type of Transient Luminous Events (TLEs); TLEs can take a variety of fanciful shapes with equally fanciful names.
This image is the NASA Science Calendar Image of the Month for December 2025. Learn more about sprites and download this photo to use as a wallpaper on your phone or computer.
Text credit: Miles Hatfield
Image credit: Nicolas Escurat