Nation ‘It’s going to be a wild ride’: NASA spacecraft Juno to fly by Jupiter’s moon Ganymede today June 7, 2021 Doyle Rice, USA TODAY Comments Off on ‘It’s going to be a wild ride’: NASA spacecraft Juno to fly by Jupiter’s moon Ganymede today Monday afternoon, NASA's spacecraft Juno will come within 645 miles of Ganymede, which is also the largest moon in the solar system.