Overview
- University of Liège researchers report that Juno’s ultraviolet spectrograph resolved Ganymede’s aurora into chains of small patches rather than a uniform curtain.
- The study, published February 18, 2026 in Astronomy & Astrophysics, reconstructs high-resolution auroral structure from narrow UVS strips gathered during the July 7, 2021 flyby.
- The patchy features resemble auroral ‘beads’ seen at Earth and Jupiter, pointing to shared magnetosphere–atmosphere coupling processes across different worlds.
- Ganymede, the only moon known with an intrinsic magnetic field, shows auroras produced by electrons precipitating into a tenuous oxygen atmosphere, according to the authors.
- Because Juno’s close look lasted under 15 minutes and will not be repeated, longer-term monitoring is deferred to ESA’s JUICE mission, slated to reach Jupiter in 2031 with a comparable UV spectrograph.