Emission from trihydrogen cations of large atmospheres flames (h3+) It has been used for over 30 years to study the global interactions of Jupiter, Saturn and Uranus with the surrounding space environment, revealing the process of aurora formation. However, despite repeated attempts, and against models that predict it should exist, this ion has proven elusive in Neptune. Currently, using observations from the NASA/ESA/CSA James Webspace telescope, astronomers have detected Neptune’s trihydrogen cations and distinct infrared South Aurorae.
This composite image, created using data from the NASA/ESA Hubble Space Telescope and the NASA/ESA/CSA James Webbspace Telescope, shows the aurora activity (cyan bevel) in Neptune. Image credits: NASA/ESA/CSA/STSCI/HEIDI HAMMEL, Aura/Henrik Mellin, University of Northumbria/Leafletcher, University of Leicester/Stefanie Millam, NASA-GSFC.
“In the past, astronomers have seen appetizing hints for Aurora’s activities in Neptune,” said Henrik Mellin, an astronomer at Northumbria University and his colleagues.
“However, imaging and confirmation of Aurorae in Neptune has been avoiding astronomers for a long time despite successful detections on Jupiter, Saturn and Uranus.”
“Neptune was a missing part of the puzzle when it came to detecting the giant planet of the solar system, Aurorae.”
In this study, the authors analyzed the obtained data. Webb’s Near-Infrared Spectroscopy (NIRSPEC) June 2023.
In addition to the image of the planet, astronomers have characterized the composition and acquired spectra to measure the temperature of the planet’s upper atmosphere (ionosphere).
They discovered a very prominent efflux system indicating the presence of trihydrogen cations.
“In Neptune’s Webb image, the glowing aurora appears as a spot, represented by cyan,” the astronomer said.
“The aurora activity seen in Neptune is markedly different from what we are used to seeing here on Earth, or even Jupiter and Saturn.”
“Instead of being trapped in the north and south poles of the planet, Neptune’s aurora is located in the mid-latitudes of the planet. Think about where South America is on Earth.”
“This is due to the strange nature of Neptune’s magnetic field, originally discovered by NASA’s Voyager 2 in 1989, tilting 47 degrees from the planet’s axis of rotation.”
“The activity of the aurora is based on where the magnetic field converges into the planet’s atmosphere, so Neptune’s aurora is far from the rotating pole.”
“The groundbreaking detection of Neptune’s Aurorae helps us understand how Neptune’s magnetic fields interact with particles flowing through far-flung areas of the solar system.
Researchers were also able to measure the temperature above the Neptune atmosphere for the first time since the flyby of the Voyager 2.
Their results suggest why Neptune’s Aurorae remained hidden from astronomers for a long time. The upper atmosphere of the Neptune was cooled several hundred degrees.
For many years, astronomers have predicted the strength of Neptune Aurorae based on temperatures recorded by Voyager 2.
“A rather cold temperature would result in a very prominent aurorae,” the scientist said.
“This cold temperature could be the reason why Neptune’s Aurorae remains undetected for a long time.”
“Dramatic cooling suggests that even though Earth is more than 30 times more seated from the Sun compared to Earth, this area of the atmosphere can change dramatically.”
result Today I’ll be appearing in the journal Natural Astronomy.
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H. Merin et al. Discovery of h3+ JWST and Neptune’s infrared aurorae. Nut AthlonPublished online on March 26th, 2025. doi:10.1038/s41550-025-02507-9
Source: www.sci.news
