Free Astronomy Magazine January-February 2022

36 JANUARY-FEBRUARY 2022 ASTRO PUBLISHING hemisphere of the moon. This result advances our understanding of the atmospheric structure of icy moons, and helps lay the groundwork for upcoming science missions which will explore Jupiter’s icy moons. Europa — one of Jupiter’s 79 moons — is both the sixth closest moon to Jupiter and the sixth largest moon in the Solar System. It is an icy orb larger than the dwarf planet Pluto O bservations by the NASA/ESA Hubble Space Telescope re- cently revealed water vapour in the atmosphere of Ganymede, one of Jupiter’s moons. A new analy- sis of archival images and spectra has now revealed that water vapour is also present in the atmosphere of Jupiter’s icy moon Europa. The anal- ysis found that a water vapour at- mosphere is present only on one Evidence of persistent water vapour atmosphere on Europa by NASA/ESA Bethany Downer W atch this Space Sparks episode to learn about how an as- tronomer has found evidence of wa- ter in Europa’s trailing atmosphere. [ESA/Hubble, NASA, N. Bartmann, JPL-Caltech, SwRI, MSSS, J. da Silva]