The new findings about Ganymede\u2019s auroras show that the fundamental physics behind these events are not unique to Earth.<\/p>\n
\u201cAuroras are also observed on Ganymede and are caused by the precipitation of electrons in its thin oxygen atmosphere,\u201d explains Philippe Gusbin, whose master\u2019s thesis in Space Sciences formed the foundation for this study. <\/p>\n
Unlike Earth, however, Ganymede\u2019s thin atmosphere offers a different environment for auroral formation, influenced heavily by the moon\u2019s interaction with Jupiter\u2019s powerful magnetosphere.<\/p>\n
![\"University](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2026\/02\/university-of-lige-sci-1200x453.jpg.webp.webp\")
Artistic views of the ultraviolet aurorae on Ganymede, based on Juno\u2019s close-up observations from 7th July 2021. As Juno flew by Ganymede at high speed, its UV spectrograph could only acquire narrow strips, combined here to display the overall shape of the aurora (left). However, when zooming on individual strips (right), it becomes apparent that this aurora is formed of a chain of patches rather than a uniform curtain. Similar auroral forms have been observed at Earth, as well as on other planets such as Jupiter or Saturn, suggesting that universal processes are at play.
Credit: NASA\/JPL-Caltech\/SwRI\/UVS\/ULi\u00e8ge\/Gusbin\/Bonfond<\/p>\n
Juno\u2019s Groundbreaking Observations of Ganymede\u2019s Aurora<\/p>\n
Before the Juno spacecraft\u2019s observations, scientists had only limited views of Ganymede\u2019s auroras. Ground-based observations, with lower spatial resolution, couldn\u2019t capture the fine details of these auroral features. Juno, with its advanced ultraviolet spectrograph, provided unprecedented high-resolution images, revealing the intricate structures of the auroras in extraordinary detail. <\/p>\n
\u201cObservations of Ganymede\u2019s auroras prior to Juno were limited by the spatial resolution of ground-based observations, and they could not resolve the small-scale structures typical of planetary auroras,\u201d Gusbin notes.<\/p>\n
These high-resolution images allowed scientists to discover a unique and fragmented structure of Ganymede\u2019s auroras. Instead of a smooth curtain of light, the auroras were observed to form in distinct patches, a phenomenon seen on Earth and Jupiter as well. This discovery could hold the key to understanding the dynamics of auroras across the solar system, especially in environments where magnetic fields play a major role.<\/p>\n
Auroras on Other Planets: A Universal Phenomenon<\/p>\n
Ganymede is not the only celestial body to showcase stunning auroras. Planets like Venus, Mars, Jupiter, Saturn, and Uranus also display their own versions of auroras, though the processes behind them vary. On Jupiter, for instance, auroras are even more intense, largely due to the planet\u2019s massive magnetosphere and energetic solar wind interactions. Similarly, auroras have been observed on Venus and Mars, where the lack of global magnetic fields causes different types of auroral phenomena. However, Ganymede stands out because it is the only moon in the solar system known to have its own intrinsic magnetic field, similar to Earth\u2019s.<\/p>\n