The Jovian aurora is the most powerful planetary aurora in the solar system; to date, however, it has not been possible to establish conclusively which mechanisms are involved in the excitation of the auroral emissions that have been observed at ultraviolet, infrared, and soft x ray wavelengths. Precipitation of Iogenic heavy sulfur and oxygen ions, downward acceleration of electrons along Birkeland currents, and a combination of both of these mechanisms have all been proposed to account for the observed auroral emissions. Modeling results reported here show that precipitating auroral electrons with sufficient energy to be consistent with the Voyager UVS observations will produce bremsstrahlung x rays with sufficient energy and intensity to be detected by the Solar Flare X Ray and Cosmic Ray Burst Instrument (GRB) on board the Ulysses spacecraft. The detection of such bremsstrahlung X rays at Jupiter would provide strong evidence for the electron precipitation mechanism, although it would not rule out the possibility of some heavy ion involvement, and would thus make a significant contribution toward solving the mystery of the Jovian aurora. ¿American Geophysical Union 1992