How Lightning Works on Jupiter—and Why It's So Extreme

A Discovery Nearly Five Decades in the Making

When NASA's Voyager 1 spacecraft swept past Jupiter in March 1979, its instruments picked up strange radio signals—descending, whistled tones scientists dubbed "whistlers." Those signals were the first direct evidence of lightning in Jupiter's atmosphere, confirming a theory that had swirled for centuries. But the radio emissions did not match the patterns produced by terrestrial lightning, leaving researchers puzzled for decades.

It took the arrival of the Juno spacecraft in 2016, and years of close-range data collection, to start unraveling the mystery. A March 2026 study led by Michael Wong at the University of California, Berkeley now shows that Jupiter's lightning bolts can pack more than 100 times the power of Earth's flashes—and may prove up to one million times stronger.

Why Jupiter's Storms Dwarf Earth's

On Earth, lightning forms when rising water vapor condenses into droplets and ice crystals. Collisions between those particles separate electrical charge, building voltage differences that eventually discharge as a bolt. Jupiter follows a similar principle—but with far more energy behind it.

The key difference is Jupiter's hydrogen-dominated atmosphere. Moist air on the gas giant is heavier than its surroundings, which means it takes enormous energy to push a storm upward through the atmosphere. Once that moist air finally rises, it unleashes that stored energy explosively at the cloud tops, generating extreme wind speeds and intense, cloud-to-cloud lightning.

"Convection operates differently on Earth and Jupiter because moist air is heavier and harder to bring upward," the Berkeley researchers explained. The result is electrical discharges of staggering scale in a planet with no solid ground for bolts to strike.

Mushballs: Jupiter's Exotic Hail

One of Juno's most surprising discoveries involves an entirely alien form of hail. At certain altitudes, ammonia acts as an antifreeze, lowering the melting point of water ice and creating a slushy ammonia-water mixture. Strong updrafts fling tiny ice particles more than 60 kilometers above the visible cloud deck. There, ammonia vapor melts the ice into liquid slush.

As these slushy droplets grow and fall, they collide with water-ice crystals hurled upward by thunderstorms far below. The friction of liquid-on-solid collisions generates static electricity—sparking what scientists call "shallow lightning" in Jupiter's upper atmosphere. The falling globs of ammonia-water slush, nicknamed "mushballs", essentially kidnap ammonia from the upper atmosphere and ferry it into Jupiter's depths.

This process solves a long-standing puzzle: instruments had repeatedly found less ammonia in Jupiter's upper atmosphere than models predicted. Mushballs appear to be the missing transport mechanism.

Stealth Superstorms and New Measurements

The 2026 Berkeley study benefited from an unusual stroke of luck. Between 2021 and 2022, storm activity in Jupiter's north equatorial belt dropped, leaving a single massive "stealth superstorm" system as the dominant feature. This allowed Juno's microwave radiometer to isolate lightning signals without interference from competing storms.

Researchers measured 613 individual pulses, averaging three flashes per second. Power estimates ranged from Earth-equivalent bolts up to more than 100 times stronger. The team cautioned that comparing radio emissions across different wavelengths introduces uncertainty—the true power could be far greater, potentially reaching the million-fold mark.

Why It Matters Beyond Jupiter

Studying Jovian lightning is not merely planetary trivia. Lightning drives chemical reactions that can produce complex molecules, a process relevant to understanding prebiotic chemistry on gas giants and their moons. Lightning also serves as a probe into atmospheric dynamics that are invisible from the surface—revealing circulation patterns, composition gradients, and energy transport deep within the planet.

As Juno continues its extended mission, each close pass over Jupiter's cloud tops adds another piece to a puzzle first glimpsed by Voyager nearly half a century ago. The storms raging on the solar system's largest planet remain among its most spectacular—and scientifically revealing—phenomena.