Data and photographs collected by the Voyagers’ cameras, magnetometers and other instruments, revealed unknown details about each of the four giant planets and their moons. Close-up images from the spacecraft charted Jupiter’s complex cloud forms, winds and storm systems and discovered volcanic activity on its moon Io. Saturn’s rings were found to have enigmatic braids, kinks and spokes and to be accompanied by myriad “ringlets”. At Uranus, Voyager 2 discovered a substantial magnetic field around the planet and ten more moons. Its flyby of Neptune uncovered three rings and six hitherto unknown moons, a planetary magnetic field and complex, widely distributed auroras. Voyager 2 is the only spacecraft to have visited the two ice giants. In August 2018, NASA confirmed, based on results by the New Horizons spacecraft, of a “hydrogen wall” at the outer edges of the Solar System that was first detected in 1992 by the two Voyager spacecraft.