The Webb telescope immortalized the auror for the first time on Neptune, revealing unpublished details on the atmosphere of the planet.
For the First time in the history of astronomical observationNASA immortalized the Neptune’s auror Thanks to the James Webb spatial telescope. The auror, luminous manifestations caused by the interaction between the energy particles of the sun and the magnetic field of a planet, had been hypothesized on Neptune already During the passage of the Voyager 2 probe In 1989, but they had never been confirmed with direct images.
I am not “polar” auror as on earth
Unlike what happens on earth, Jupiter and Saturn, Nettuno’s aurore are not found at the poles but to medium latitudes, due to the‘unusual inclination of the magnetic field of the planet (47 ° compared to the rotation axis). This data was already known, but now, thanks to the sensitivity to the infrared of the Webb telescope, It was possible to observe its visual effects With unprecedented precision.
The data, collected in June 2023 through the WEBB NIRSPEC spectrographerhave made it possible to detect clearly the presence of H₃⁺ (triiodruro of hydrogen), A molecule considered a distinctive sign of the auroral activity in the gaseous planets.
Surprise: the temperature decreased by hundreds of degrees
Another surprising figure concerns The temperature of the upper atmosphere of Neptunewhich, compared to the passage of Voyager 2, is fall of several hundred degrees. This could explain why until today The earlier have remained invisible: The too cold atmosphere attenuated its brightness. The discovery opens New prospects on the dynamics of giant planets of the Solar System.
According to the team led by Henrik Melin (Northumbria University) and Leigh Fletcher (University of Leicester), the study of Nettuno’s auror will help better understand the interactions between the solar wind and the magnetic fields in the Pianetthe most distant.
