James Webb Space Telescope sees Jupiter moons in a new light

Last year, JWST made spectral observations of Ganymede and infrared observations of Io. Absorption lines of hydrogen peroxide at Ganymede's poles indicate radiolysis of water ice by charged particles funneled by the moon's magnetic field. Io had two major eruptions, one associated with a forbidden emission line of sulfur monoxide. The latter supports a theory that SO is produced at volcanic vents in a thin atmosphere that allows forbidden emission before collisions destroy the excited state.