Jupiter's Lightning Could Be Almost Unbelievably Powerful

Jupiter is not Earth, and its lightning wants you to understand that in your bones.

A study published March 20 in the journal AGU Advances finds that lightning on the gas giant ranges from roughly Earth-equivalent to at least 100 times more powerful per bolt — with one estimate putting the strongest strikes at up to 10,000 times the energy of a terrestrial flash. The headline number circulating in some coverage, one million times, is a real number in the paper. It is also an upper bound the authors themselves flagged as uncertain, because it requires comparing Jupiter emissions at one radio wavelength to Earth lightning at another — a methodology Wong acknowledged introduces real uncertainty. The defensible floor is 100 times. Everything above that is an estimate, not a measurement.

The work comes from Michael Wong, a planetary scientist at the University of California, Berkeley Space Sciences Laboratory, and colleagues from the U.S., Czech Republic and Japan. Wong analyzed 613 microwave pulses collected during four close passes of NASA's Juno spacecraft between 2021 and 2022. Juno was not designed for this measurement — its Microwave Radiometer instrument was built to probe atmospheric composition beneath Jupiter's cloud tops, not to catalog lightning. But the spacecraft has now logged enough passes through Jovian storm regions to make a statistical argument unavoidable.

The lightning came from what researchers call stealth superstorms: persistent weather systems that reshaped Jupiter's cloud structure on a global scale over months, but without the towering cloud pillars of a classic Jovian superstorm. The physics here is instructive. On Earth, moist air rises because it is lighter than the dry air around it — convection is the engine of our thunderstorms. On Jupiter, the atmosphere is hydrogen-dominated, and moist air — containing water and ammonia ice crystals — is actually heavier than the surrounding gas. The charging mechanism involves slushy water-ammonia particles falling through the atmosphere like hail that happens to zap things on the way down.

Jupiter's storms themselves dwarf terrestrial ones in scale: they extend more than 100 kilometers vertically, compared to roughly 10 kilometers for an Earth thunderstorm. Wong estimates the energy in a Jovian bolt ranges up to 500, and possibly 10,000, times the roughly 1 gigajoule released by an average Earth strike — enough to power 200 average American homes for an hour. The flash rate during Juno's closest passes hit three per second, with a single flyover capturing 206 distinct pulses.

The science is solid, and it arrives at an awkward moment. Louise Prockter, director of NASA's Planetary Science Division, told Ars Technica that the agency cannot afford to support every extended mission it has historically funded. Juno — cruising around Jupiter since 2016 — is humanity's only active spacecraft operating between the orbit of Jupiter and Pluto. About 10 percent of the Planetary Science budget, roughly $260 million in fiscal year 2025, goes to extended missions like Juno. Congress passed a fiscal year 2026 budget of $2.54 billion for the division, well above the White House's request but about $220 million below the prior year. The annual operating plan that will determine Juno's fate is due to Congress soon.

None of this changes the physics. The 613 pulses are in the literature. Jupiter's lightning occupies a power spectrum we have never observed anywhere else in the solar system. The upper bound on bolt energy is uncertain; the lower bound is not. The question of whether NASA can afford to keep listening is a separate one — and right now, it is an open question.