This mission will be very dangerous for the probe. It will face large amounts of radiation, gravity and the largest magnetosphere in the solar system. No probe in history has come this close to Jupiter
spaceexp: A montage of New Horizons images of Jupiter and its volcanic moon Io, taken during the spacecraft’s Jupiter flyby in early The image shows a major eruption in progress on Io’s night side, at the northern volcano Tvashtar
Callisto - Fourth moon of Jupiter after Io - Europa - Ganymede. Formed of rock and ices Third largest moon in our solar system after Titan (Saturn) and Ganymede (Jupiter) respectively. Jupiter's Io being fourth and our Luna fifth.