[P-PS01] Outer Solar System Exploration Today, and Tomorrow

[PPS01-06] Observations of tenuous atmospheres at Jupiter’s icy Galilean moons: HST and future missions

★Invited Papers

*Lorenz Roth¹ (1.KTH Royal Institute of Technology, Space and Plasma Physics, Stockholm, Sweden)

キーワード：Jupiter, Galilean moons, satellite atmospheres, Hubble Space Telescope, Jupiter moon missions

In this presentation, the UV observations by the Hubble Space Telescope (HST) of the tenuous atmospheres of Jupiter’s large icy moons are reviewed. We discuss the previous detections of O2 at Europa and Ganymede through auroral emissions and at Callisto through photo-electron emissions. In addition, we show new results from the HST data that reveal the presence of sublimated H2O atmospheres in the sub-solar region in addition to O2. HST also discovered atomic hydrogen coronae at all three moons and measured localized H and O atomic emissions at Europa, interpreted as first evidence for the existence of plumes. At the end, we give an overview on future measurements of the icy moon atmospheres by ESAs JUpiter Icy Moon Explorer (JUICE) and NASAs Europa Clipper mission, with focus on the UVS instruments.