IUE Observations of the Jovian dayglow emission

IUEssspectra of Jupiter are examined in light of recent models put forward to explain the anomalously bright ultraviolet emissions seen from the upper atmospheres of the outer planets. Chi‐squared fits of the IUE spectra with model spectra produced by two proposed excitation mechanisms, electron impact and fluorescence of solar radiation, result in consistently higher χ² values for the solar fluorescence model. We find no conclusive evidence in the IUE data for the dominance of solar fluorescence over electron excitation in producing the Jovian dayglow emission.