Green spots show where Auroras lights the sky of Neptune
NASA, ESA, CSA, STSCI, Heidi Hammel (Aura), Henrik Melin (Northumbria University), Leigh Fletcher (University of Leicester), Stefanie Milam (NASA-GSFC)
For the first time, the researchers spotted dawn infrared swirling in the atmosphere of Neptune, checking decades of scientific speculation.
When the NASA Voyager 2 mission flew by Neptune in 1989, it found attractive clues of Aurora activity In the clouds of the ice giant. However, scientists could not verify the phenomenon at the time, because the existing instruments were too weak. Now, the James Webb space telescope (JWST) finally provided the power to detect them.
“It was really a realization of years of anticipation of years,” says Heidi Hammel At the association of Universities for Research in Astronomy in Washington DC.
Hammel and his colleagues used Nirspec de JWST, a powerful infrared imaging tool, to capture spectroscopic neptune images and analyze the different light wavelengths emitted by the planet. In 2023, researchers used the instrument to detect Infrared auroras on Uranus. This time, it also found them on Neptune.
The images also allowed Hammel and his team to start building a map of the Magnetic field of Neptune. This is particularly exciting because the planet is known to have some of the most unusual magnetic poles in the solar system.
Unlike the earth, Jupiter or Saturn, Neptune's magnetic posts are not centered on its poles of rotation. Instead, “they are offset by almost half of the planet's department,” said Hammel. Consequently, its aurorae appear as irregular blobs much closer to its equator, on roughly the region where South America is on earth.
In addition to detect the dawn, JWST observations indicate that the Neptune ionosphere – the layer of loaded particles which cover certain planets – cools. It is now, on average, about 10% colder than when traveling 2 has passed almost 36 years ago. Similar changes have been detected on Uranus.
Although the authors of the new study do not know why this cooling has happened, they hope that their next JWST observation period, scheduled for 2026, will offer more signs.
From striking alpine forests to the picturesque snowy mountains, travel to northern Sweden during the winter months offers a truly magical experience.
Science of astronomy and ice: Sweden
