Mysterious Abundance of Oxygen on Jupiter's Moon Callisto Baffles Scientists

Jupiter's moon Callisto, the third-largest moon in the Solar System, has been found to have a significant amount of oxygen, much more than expected. Previous experiments suggested that the oxygen was produced through electronic sputtering and chemical reactions, but the observed amount of oxygen exceeds these predictions by several orders of magnitude. Scientists are now seeking to understand the source of this excess oxygen through future observations, such as those planned during the upcoming JUICE mission to Jupiter's icy moons.