Jupiter’s storms are big enough to dominate the planet, and now scientists say some of their lightning bolts may hit far harder than anything seen on Earth.

Using data from NASA’s Juno spacecraft, researchers at the University of California, Berkeley found that some lightning flashes on Jupiter may be 100 times stronger than lightning on Earth, and possibly even more intense. The study was published in AGU Advances.

The findings come from Juno’s microwave radiometer, which has been studying Jupiter’s atmosphere since the spacecraft entered orbit around the planet in 2016. The instrument can detect radio emissions produced by lightning. Researchers said that gave them a way to estimate lightning energy because microwave signals can pass through clouds.

Lead author Michael Wong, a planetary scientist at UC Berkeley’s Space Sciences Laboratory, said storms on other planets can also help scientists study weather closer to home.

“There’s so much we don’t know about lightning on Earth,” Wong said.

Wong said convection works differently on Jupiter because its atmosphere is dominated by hydrogen. “Convection operates a little bit differently on Earth and Jupiter because Jupiter has a hydrogen-dominated atmosphere, so moist air is heavier and harder to bring upward,” he said.

That means storms on Jupiter need much more energy to rise through the atmosphere. Once they do, researchers said, they can release enormous amounts of energy and produce powerful cloud-to-cloud lightning.

Nearly every spacecraft that has visited Jupiter has detected lightning. Earlier missions suggested the planet’s lightning was exceptionally powerful because they could only detect the brightest flashes. But Juno’s highly sensitive star-tracking camera later picked up many weaker flashes that were more comparable to lightning on Earth.

Visible-light observations have limits because clouds can hide some flashes, making it hard to judge their true brightness. Juno’s microwave radiometer offered another way to measure them, although the instrument was not specifically designed to study lightning.

Scientists got a clearer shot in 2021 and 2022, when storm activity in Jupiter’s North Equatorial Belt temporarily dropped. That let Wong and his team focus on isolated storms one at a time.

Using observations from the Hubble Space Telescope, Juno’s onboard camera and images captured by amateur astronomers, the team identified several unusual storms that Wong called “stealth” superstorms. He said they lasted for months and dramatically changed nearby cloud patterns, even though their cloud towers remained relatively modest in height.

“Because we had a precise location, we were able to just say, ‘OK, we know where it is. We’re directly measuring the power,’” Wong said.

During that quieter period, Juno made 12 passes over isolated storms. On four flyovers, the spacecraft came close enough to measure microwave signals from lightning. Scientists recorded an average of three lightning flashes per second during those passes. In one encounter, Juno detected 206 separate microwave pulses.

Out of 613 measured pulses, the team estimated that the lightning ranged from roughly the strength of Earth lightning to more than 100 times stronger. Wong said there is still uncertainty in the comparison because Jupiter and Earth lightning were measured at different radio wavelengths.

One previous study suggested Jupiter’s lightning could potentially be a million times more powerful than lightning on Earth.

Co-author Ivana Kolmašová, a space physicist at Charles University in Prague, Czechia, and a member of the Czech Academy of Sciences, said measuring the total energy of a lightning bolt is complicated because lightning releases energy in several forms, including radio waves, light, heat, sound and chemical reactions.

On Earth, a typical lightning bolt releases about 1 gigaJoule of energy, or one billion joules. Wong estimates that lightning on Jupiter may release from 500 to possibly 10,000 times more energy than Earth lightning.

Researchers think Jupiter’s lightning forms in a similar way to thunderstorms on Earth, with rising water vapor condensing into droplets and ice crystals that become electrically charged. On Jupiter, scientists think storms may produce icy slush-like objects called “mushballs,” formed when water and ammonia combine.

Researchers still do not fully understand why Jupiter’s lightning can become so powerful.

“This is where the details start to get exciting, where you can ask, ‘Could the key difference be hydrogen versus nitrogen atmospheres, or could it be that the storms are taller on Jupiter and so there’s greater distances involved?’” Wong said.

Jupiter’s storms can rise more than 100 kilometers high, compared to roughly 10 kilometers for storms on Earth.

“Or could it be that greater energy is available because with moist convection on Jupiter, you have a bigger buildup of heat needed before you can generate the storm to create lightning?” he added. “It’s an active area of research.”

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