Jupiter’s atmosphere is a fascinating, ever-changing environment. Bands of different colors, storms, massive clouds, and more can be seen all over the planet. However, the upper atmosphere has long been considered uneventful. It certainly has aurora borealis, but other than that, it was thought nothing strange was happening. Now, a group of astronomers has turned that belief on its head.
The upper atmosphere is difficult to study. At the poles, particles from the volcanic moon Io follow magnetic field lines to create auroras at multiple wavelengths. As for the rest of the planet, the energy that forms it is sunlight. Jupiter receives only about 4% of the sunlight that Earth receives. That’s why astronomers assumed the aurora would be very uniform.
“We thought, perhaps naively, that this area would be really boring,” said team leader Henrik Melin, from the University of Leicester in the UK. statement“It’s actually as interesting as the northern lights, if not more interesting. Jupiter never ceases to amaze us.”
Observations by the James Webb Telescope have revealed complex structures above the famous Great Red Spot, a storm wider than Earth. They found dark arcs and bright spots that can be seen in infrared. The source of this diversity is not sunlight, but rather the deeper, chaotic layers of Jupiter’s atmosphere.
“One way you can change this structure is with gravity waves, which are like waves crashing on a beach, creating ripples in the sand,” Melin explained. “These waves are generated deep in the turbulent lower atmosphere, around the Great Red Spot, and can travel upward, changing the structure and emissions of the upper atmosphere.”
These gravitational waves also exist on Earth, but if the influencing mechanism is the same, they are much weaker.
The discovery has been a long time coming. These observations were part of JWST’s Early Launch Science (ERS) program, where astronomers have been curious about Jupiter’s upper atmosphere for a while.
“This ERS proposal was written in 2017,” said team member Imke de Pater of the University of California, Berkeley. “One of our goals was to investigate the cause of the high temperature above the Great Red Spot, as revealed by recent observations by NASA’s Infrared Telescope Facility. However, our new data showed very different results.
The team hopes to follow up observations with the James Webb Space Telescope to better understand this part of the Jovian atmosphere. It will also help with planned observations for the European Space Agency’s JUICE mission, which will explore the planet and its three icy moons.
These results were published in Nature astronomy.
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