Three-year of observations of Jupiter’s aurora and Io plasma torus variabilities by earth orbiting extreme-ultraviolet spectroscope HISAKI

Extreme Ultraviolet spectrograph, EXCEED, on-board the HISAKI satellite is designed for observing tenuous gas and plasma around planets in the solar system. It enables us to obtain continuous and long-term data set and find time variability in the planetary magnetosphere and ionosphere with time scales of several hours to months. Here, we introduce new findings of Jupiter's UV aurora and plasma emissions from the Io plasma torus obtained from the HISAKI observation.