These signals were recorded by the Voyager 1 plasma wave instrument as the spacecraft flew past Jupiter on March 5, 1979. Jovian whistler waves propagate at audio frequencies along closed field lines in Jupiter’s magnetosphere. Like Earth whistlers, the higher frequency components of the Jovian whistler propagate faster than the lower frequency components, resulting in a descending whistling tone. Also like Earth whistlers, Jovian whistlers are generated by lightning discharges in the atmosphere. It was th