Neptune’s auroras captured in detail for first time

By Dean Murray

Auroras on Neptune have been captured in detail for the first time.

NASA’s James Webb Space Telescope spotted bright auroral activity on the most distant planet in our solar system.

The space agency said on Wednesday (March 26) that astronomers had previously seen tantalizing hints of auroral activity on Neptune, for example, in the flyby of NASA’s Voyager 2 in 1989.

However, imaging and confirming the auroras there had evaded astronomers, despite successful detections on Jupiter, Saturn, and Uranus.

Henrik Melin of Northumbria University, lead author of the paper published in Nature Astronomy, conducted the research while at the University of Leicester.

He said: "Turns out, actually imaging the auroral activity on Neptune was only possible with Webb’s near-infrared sensitivity. It was so stunning to not just see the auroras, but the detail and clarity of the signature really shocked me."

Leigh Fletcher of Leicester University, paper co-author, said: "As we look ahead and dream of future missions to Uranus and Neptune, we now know how important it will be to have instruments tuned to the wavelengths of infrared light to continue to study the auroras.

"This observatory has finally opened the window onto this last, previously hidden ionosphere of the giant planets."

The data was obtained in June 2023 using Webb’s Near-Infrared Spectrograph. The observations, led by Fletcher, were taken as part of Hammel’s Guaranteed Time Observation program 1249.