NASA’s newly launched Webb Space Telescope has successfully captured bright auroras on Neptune, the most distant planet in our solar system. The discovery confirms long-held suspicions about the presence of auroral activity on Neptune.
For decades, astronomers have observed tantalizing hints of aurora-like activity on Neptune during Voyager 2’s flyby in 1989. However, imaging and confirming these events proved elusive, unlike on Jupiter, Saturn, and Uranus. The reason for this lack of detection lies in the unique nature of Neptune’s magnetic field, which is tilted at an angle of 47 degrees from its rotation axis.
The Webb Telescope’s near-infrared sensitivity made it possible to image auroral activity on Neptune, revealing a distinct difference from what we see on Earth or other planets. Unlike polar auroras, Neptune’s auroras are located at mid-latitudes, similar to South America’s location on our planet.
Neptune’s magnetic field convergence with its atmosphere creates this unique phenomenon. “This observatory has finally opened the window onto this last, previously hidden ionosphere of the giant planets,” said Leigh Fletcher, co-author of the paper.
The study also revealed a mystery: Neptune’s upper atmosphere has cooled by hundreds of degrees since Voyager 2’s flyby in 1989. This temperature drop is likely responsible for the long-standing lack of aurora detection on Neptune. The dramatic cooling suggests that this region can undergo significant changes despite being far from the Sun, which is 30 times farther away than Earth.
This groundbreaking discovery demonstrates the importance of having instruments sensitive to infrared light for future missions to Uranus and Neptune. As astronomers look ahead to these next-generation missions, they now understand the significance of capturing auroral activity in this region.
Source: https://www.goodnewsnetwork.org/neptunes-long-hidden-auroras-are-captured-for-the-first-time-revealing-a-new-mystery