Auroras on Jupiter flash in seconds, defying old models
The largest planet in the solar system is putting on a show no telescope has fully caught before. New data from the James Webb Space Telescope (JWST) shows Jupiter’s auroras are flickering in bursts measured in seconds, not minutes. Scientists now face fresh questions about where that power comes from.
Electric-blue aurora at Jupiter’s north pole with bright spots marking magnetic footprints of its moons Io, Ganymede, and Europa. Captured by the Hubble Space Telescope. Image credit: NASA/ESA and John Clarke
Recent observations from the National Aeronautics and Space Administration’s (NASA) James Webb Space Telescope (JWST) have revealed anomalous details in Jupiter’s auroral activity. The giant gas planet’s auroras are extremely bright and more intense than those on Earth.
Auroral drivers in Jupiter’s magnetosphere
Auroras on Earth form when solar storms hurl charged particles into the upper atmosphere. These particles collide with gases like oxygen and nitrogen, making the sky glow in reds, greens, and purples. On Jupiter, there’s plenty more at play. Its immense magnetic field captures additional charged particles from the space around it, fueling powerful auroral displays.
Webb’s infrared sensitivity allowed the team to resolve auroral dynamics down to 3-second intervals. This resolution is nearly 100 times faster than what ground-based telescopes could previously manage. The final observations revealed rapid flickering and localized bursts of infrared light invisible in earlier studies.
On December 25, 2023, researchers led by Jonathan Nichols at the University of Leicester used Webb’s Near-Infrared Camera (NIRCam) to gather detailed observations. These findings are helping scientists better understand how Jupiter’s auroral activity shifts over time. Nichols described the experience, saying that the team had expected the auroras to shift slowly, perhaps dimming and brightening over about fifteen minutes. Instead, they were astonished to see the entire auroral region flickering rapidly, with changes occurring in just seconds.
Jupiter draws in a constant stream of charged particles because of its powerful magnetic field. Some come from the Sun, carried by the solar wind. Others originate from one of Jupiter’s moons, called Io.
Io’s frequent volcanic eruptions release large amounts of sulfur and oxygen ions that enter Jupiter’s magnetic field. As these particles spiral along magnetic field lines, they gain speed and energy. When they eventually crash into Jupiter’s upper atmosphere, they trigger intense bursts of light. These ions contribute to unique auroral structures like the Io footprint tail, where bursts of infrared emission are seen propagating at speeds of around 67 km/s (150 000 mph).
Energy variability in Jupiter’s aurora
JWST’s advanced instruments helped detect subtle and rapid changes in the trihydrogen ion (H₃⁺) emissions across different regions near the poles. This ion forms during auroras and glows in infrared light.
The team modeled the infrared emission’s delay and decay compared to ultraviolet bursts, enabling them to calculate an H3⁺ lifetime of 150 ± 4 seconds. Earlier estimates had ranged from 10 seconds to more than 15 minutes. This precise measurement also allowed them to estimate the electron density in Jupiter’s upper ionosphere to be about 5.8 × 10⁴ cm⁻³.
The observations showed that the Dusk Active Region (DAR) was the brightest and most variable part of Jupiter’s aurora in the infrared. This region had no ultraviolet counterpart in Hubble’s data. This mismatch suggests energy is being deposited or radiated in ways not currently accounted for by standard models.
Unexplained emission patterns and future investigation
The newly identified pattern also included Rapid Eastward-Travelling Auroral Pulses (REAPs). These pulses were seen racing across Jupiter’s dawn-side polar region at speeds near 60 km/s (37.3 mi/s), with a periodicity of around 1.6 minutes. These fast-moving pulses don’t fit into existing models of how disturbances move through Jupiter’s magnetic field.
The brightness recorded by both Webb and Hubble would require a large number of very low-energy particles hitting Jupiter’s atmosphere. Until now, scientists didn’t think this was possible. Now the team is working to understand the root of this.
The researchers are now preparing to investigate the differences between the Webb and Hubble observations in more detail with the help of NASA’s Juno. They intend to learn what these differences might reveal about the conditions in Jupiter’s upper atmosphere and nearby space.
References:
1Dynamic infrared aurora on Jupiter – J. D. Nichols, O. R. T. King, et al. – Nature Communications – May 12, 2025 – DOI https://www.nature.com/articles/s41467-025-58984-z – OPEN ACCESS
2NASA’s Webb Reveals New Details, Mysteries in Jupiter’s Aurora – NASA – May 12, 2025
My passions include trying my best to save a dying planet, be it through carpooling or by spreading awareness about it. Research comes naturally to me, complemented by a keen interest in writing and journalism. Guided by a curious mind and a drive to look beyond the surface, I strive to bring thoughtful attention and clarity to subjects across Earth, sciences, environment, and everything in between.
I am not surprised. The current models are missing the most important ingredient. But, institutional scientists aren’t coming to their senses and allowing true scientific progress.