Webb telescope reveals hidden activity on Jupiter's moon Callisto

New observations from the James Webb Space Telescope's near-infrared spectrograph show that Callisto, long considered the quietest of Jupiter's large moons, has more dynamic surface processes than previously thought. The instrument mapped water ice in unprecedented detail, revealing sharp concentrations around impact basins like Valhalla and Asgard on the leading hemisphere, while the trailing hemisphere shows a distinct ice pattern that strengthens toward higher latitudes. The findings, led by Caltech's Maria Camarca, have been accepted for publication in the Planetary Science Journal.