Detection of H3+ on Jupiter
Atreya, S. K.; Drossart, P.; Clarke, J. T.; Waite, J. H.; Caldwell, J.; Tennyson, J.; Kim, S. J.; Wagener, R.; Miller, S.; Maillard, J. -P.; Watson, J. K. G.; Majewski, W. A.
France, Canada, United States
Abstract
SINCE their detection in the high latitudes of Jupiter, first by the Voyager Ultraviolet Spectrometer (UVS) experiment1,2, then by the International Ultraviolet Explorer (IDE) satellite3, the auroral particle precipitations have been associated with various phenomena in the jovian environment. In the magnetosphere, the H+3 ion, probably of ionospheric origin, was detected in situ by the Voyagers4. Infrared emissions were observed in spectral bands characteristic of CH4 (ref. 5) and of other hydrocarbons6,7, localized in two auroral spots5,8. Here we present high-resolution spectra at a wavelength of 2 μm, in the southern auroral region of Jupiter, recorded at the Canada-France-Hawaii Telescope (CFHT), which we believe to be the first astronomical spectroscopic detection of H3+. The derived rotational temperature of H3+ is in the range 1,000-1,200 K. Such strong H3+ lines could be used in future ground-based monitoring of the jovian auroral activity and to search for this molecular ion in the interstellar medium.