New images from the James Webb Space Telescope reveal Neptune's auroras in unprecedented detail. This marks a significant milestone in observing the distant planet's atmospheric phenomena.
While hints of these auroras were initially detected in ultraviolet light by Voyager 2 in 1989, Webb's infrared capabilities have provided the most compelling evidence of their existence to date.
The National Aeronautics and Space Administration (NASA) unveiled these captivating images on Wednesday, with the findings subsequently published in Nature Astronomy.
Planetary auroras are created when charged particles from space interact with atmospheric molecules, triggering reactions that emit light.
On Earth, these auroras manifest as the northern and southern lights, typically observed near the poles.
Although scientists have extensively studied auroras on Saturn and Jupiter, Neptune's remote location has made close observation challenging.
According to James O’Donoghue, a planetary scientist at the University of Reading and co-author of the study, Neptune has long been a difficult target. He noted that its auroras had only been observed by Voyager, prompting ongoing efforts to revisit them.
O'Donoghue explained that Neptune’s auroras appear closer to the planet's mid-latitudes, rather than the polar regions, due to variations in its magnetic field.
Heidi Hammel, a co-author from the Association of Universities for Research in Astronomy, confirmed that the Webb telescope provided the “first robust detection” of Neptune’s auroras, more than 30 years after Voyager 2’s initial observation.
The research team also discovered a significant cooling trend in Neptune’s atmosphere since the 1980s, potentially affecting the intensity of the auroral displays.