What Are Red Sprites and Blue Jets Above Thunderstorms?

Red sprites and blue jets are massive plasma discharges that occur in the upper atmosphere above thunderstorms, shooting upward toward space at incredible speeds. These phenomena remained undetected by science until 1989, despite occurring above every major storm system on Earth.

The Accidental Discovery That Changed Atmospheric Science

For thousands of years, humans observed thunderstorms without realizing that spectacular light shows were occurring directly above them. In July 1989, University of Minnesota researchers accidentally pointed a low-light camera at a storm system and captured something that stunned the scientific community worldwide. The footage revealed massive red plasma bursts erupting above the clouds—silent, enormous, and completely unknown to science.

This accidental discovery opened an entirely new field of atmospheric research. Prior to 1989, pilots occasionally reported strange flashes above storms, but their accounts were largely dismissed by the scientific establishment. The photographic evidence changed everything, proving that the upper atmosphere harbors phenomena far more complex than previously imagined.

Understanding Sprites: Cold Plasma, Not Lightning

Despite their explosive appearance, sprites are not actually lightning. These red plasma discharges are cold phenomena, producing almost no heat despite looking like raging electrical explosions. They occur at altitudes between 50 and 90 kilometers above Earth’s surface, in the mesosphere, where the atmosphere is extremely thin.

Sprites can extend up to 50 kilometers vertically and appear as red jellyfish-like structures with trailing tendrils. They last only milliseconds but cover enormous areas of sky. The red coloration comes from excited nitrogen molecules in the thin upper atmosphere, creating a distinctly different spectral signature than traditional lightning.

Blue Jets: Rocket-Speed Atmospheric Phenomena

Blue jets represent an even more dramatic atmospheric display. These phenomena rocket upward from storm tops at approximately 100 kilometers per second, reaching altitudes of 40 to 50 kilometers—nearly the edge of the stratosphere. Unlike sprites, blue jets originate directly from the thunderstorm’s cloud tops and shoot straight up in narrow cones.

The blue coloration results from excited oxygen and nitrogen molecules at different atmospheric pressures than those that create sprites. Blue jets typically last longer than sprites, sometimes persisting for several hundred milliseconds as they propagate upward through the atmosphere.

ELVES: The Fastest Light Show on Earth

Above sprites exists an even more remarkable phenomenon called ELVES (Emissions of Light and Very Low Frequency Perturbations due to Electromagnetic Pulse Sources). These appear as expanding discs of optical light up to 400 kilometers wide, spreading at nearly the speed of light. ELVES last less than a millisecond, making them among the fastest optical phenomena in Earth’s atmosphere.

ELVES occur at altitudes around 85-95 kilometers and are triggered by electromagnetic pulses from powerful lightning strikes. The expanding ring of light represents the ionization of atmospheric particles by the electromagnetic wave as it propagates outward from the lightning source.

Modern Research and Space-Based Observations

Today, scientists actively study these phenomena using sophisticated equipment aboard the International Space Station. A dedicated instrument now captures these events from orbit, providing unprecedented views of upper-atmospheric electrical activity. Researchers are investigating whether sprites, blue jets, and ELVES play crucial roles in regulating Earth’s global electrical circuit.

This research has revealed that these phenomena occur far more frequently than initially suspected. Every major thunderstorm system likely produces some form of upper-atmospheric discharge, suggesting these events are fundamental components of Earth’s electrical system rather than rare curiosities.