NASA’s Webb space telescope has captured haunting new views of Jupiter’s auroral display, revealing the bright light show in exquisite, never-before-seen details. Using the telescope’s most recent observations of the gas giant, scientists uncovered a curious discrepancy between how Jupiter’s auroras appear to Webb versus Hubble.
Webb’s NIRCam (Near-Infrared Camera) zoomed into Jupiter’s poles to capture the planet’s fast-varying auroral features, which are 100 times brighter than the ones seen on Earth.
“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,” Jonathan Nichols, a researcher at the University of Leicester in the United Kingdom, and lead author of a new paper published in the journal Nature Communications, said in a statement. “Instead, we observed the whole auroral region fizzing and popping with light, sometimes varying by the second.”
On Earth, auroras take place when energetic particles from the Sun interact with the planet’s magnetic field and its atmosphere, creating shimmering displays of light across the skies known as the Northern and Southern Lights. Aside from the Sun’s particles, Jupiter has an additional source that creates its auroras. Jupiter’s strong magnetic field grabs charged particles from its surroundings and accelerates them to high speeds. These speedy particles, some of which are thrown into space by Jupiter’s orbiting moon Io, slam into the planet’s atmosphere at high energies and excite the gas, causing it to glow.
Using Webb’s recent observations of Jupiter’s aurora, the scientists studied emissions from a molecule called trihydrogen cation. The special molecule is formed when energetic particles rip an electron off of a hydrogen molecule, and that molecule then reacts with other hydrogen molecules. The study found that the trihydrogen cation emissions are far more variable than they previously believed. Understanding the behavior of the special molecule helps scientists better understand how Jupiter’s atmosphere cools and heats.
The scientists also took images of Jupiter’s auroras with NASA’s Hubble Space Telescope at the same time Webb made its observations, capturing them in ultraviolet light. They uncovered a strange discrepancy between the two sets of data, the brightest light observed by Webb had no real counterpart in the Hubble images.
“This has left us scratching our heads,” Nichols said. “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.”
The team plans on carrying out follow-up observations of Jupiter’s auroras using Webb and compare them to data collected by the ongoing Juno mission. The spacecraft has been orbiting the gas giant since 2016, capturing Jupiter and its moons in exquisite detail. Webb previously captured images of Jupiter’s glowing auroras at its north and south poles, providing scientists with a new perspective of the planet’s light display in infrared wavelengths.
