Webb sees the aurora flickering, fluctuating, and undulating at Jupiter's north pole.

Auroras on Earth, better known as the Northern and Southern Lights, create glowing, shifting curtains of color in the night sky. These dazzling displays happen when high-energy particles from the Sun are steered by Earth's magnetic field and crash into the atmosphere near the poles. Even astronauts aboard the International Space Station can see them from above.

Now imagine that light show cranked up to an extreme. On Jupiter, auroras are not only much larger but also hundreds of times brighter than those on Earth. When astronomers pointed NASA's powerful James Webb Space Telescope at the giant planet, they discovered something surprising: Jupiter's auroras don't just glow, they burst and flicker like cosmic fireworks, sometimes changing in just seconds.

Webb Space Telescope Reveals New Details, Mysteries in Jupiter's Aurora

NASA's James Webb Space Telescope has revealed stunning new details about the brilliant auroras shining over Jupiter, the largest planet in our solar system. These glowing light shows are not only massive but also hundreds of times brighter than Earth's auroras. Thanks to Webb's incredible sensitivity, astronomers are now able to study these lights in greater detail to better understand Jupiter's powerful magnetic environment.

Auroras occur when streams of high-energy particles crash into a planet's atmosphere near its magnetic poles, causing gases to glow. On Earth, we know them as the Northern and Southern Lights -- shimmering displays that appear when particles from the Sun interact with the upper atmosphere, producing colorful waves of red, green, and purple light. Jupiter's auroras are far more intense and energetic, fueled by additional cosmic forces.

Volcanic Moons and a Magnetic Juggernaut

One major difference is that Jupiter doesn't just rely on the Sun for its auroras. Its massive magnetic field also pulls in charged particles from its surroundings, including material thrown into space by its moon Io. Known for its explosive volcanoes, Io blasts out particles that escape the moon's gravity and form a ring around Jupiter. When these and other solar particles are swept up by Jupiter's magnetic field, they're accelerated to extreme speeds and collide with the planet's atmosphere, creating bursts of glowing light.

Webb is now offering an unprecedented look at these events. Using its Near-Infrared Camera (NIRCam), the telescope captured new data on December 25, 2023. Led by Jonathan Nichols at the University of Leicester in the UK, the research team discovered rapidly changing features in Jupiter's auroras, revealing a level of activity that's far more dynamic than scientists expected.

NASA's James Webb Space Telescope has captured new details of the auroras on our solar system's largest planet. The dancing lights observed on Jupiter are hundreds of times brighter than those seen on Earth.

Flickering in Seconds: A Shocking Discovery

"What a Christmas present it was - it just blew me away!" shared Nichols. "We wanted to see how quickly the auroras change, expecting them to fade in and out ponderously, perhaps over a quarter of an hour or so. Instead, we observed the whole auroral region fizzing and popping with light, sometimes varying by the second."

In particular, the team studied emission from the trihydrogen cation (H), which can be created in auroras. They found that this emission is far more variable than previously believed. The observations will help develop scientists' understanding of how Jupiter's upper atmosphere is heated and cooled.

The team also uncovered some unexplained observations in their data.

A Tale of Two Telescopes

"What made these observations even more special is that we also took pictures simultaneously in the ultraviolet with NASA's Hubble Space Telescope," added Nichols. "Bizarrely, the brightest light observed by Webb had no real counterpart in Hubble's pictures. This has left us scratching our heads. In order to cause the combination of brightness seen by both Webb and Hubble, we need to have a combination of high quantities of very low-energy particles hitting the atmosphere, which was previously thought to be impossible. We still don't understand how this happens."

These observations of Jupiter's auroras at a wavelength of 3.36 microns (F335M) were captured with Webb's NIRCam (Near-Infrared Camera) on December 25, 2023.

What Comes Next for Jovian Auroras

The team now plans to study this discrepancy between the Hubble and Webb data and to explore the wider implications for Jupiter's atmosphere and space environment. They also intend to follow up this research with more Webb observations, which they can compare with data from NASA's Juno spacecraft to better explore the cause of the enigmatic bright emission.

These results were published today in the journal Nature Communications.

Reference: "Dynamic infrared aurora on Jupiter" by J. D. Nichols, O. R. T. King, J. T. Clarke, I. de Pater, L. N. Fletcher, H. Melin, L. Moore, C. Tao and T. K. Yeoman, 12 May 2025, Nature Communications.

DOI: 10.1038/s41467-025-58984-z