DETECTION OF H-3+ INFRARED-EMISSION LINES IN SATURN

Three emission lines of the nu2 fundamental vibration-rotation band of H-3+ have been detected in the ionosphere of Saturn near and at its poles. The peak observed column density of H-3+ (at the south limb) is more than two orders of magnitude lower than the column density at the south pole of Jupiter and is less than that detected from Uranus. While the number and the signal-to-noise ratios of observed transitions are not sufficient to determine the temperature and abundance of H-3+ accurately, the observed emission intensities are consistent with a temperature of almost-equal-to 800 K and total column density of almost-equal-to 1.0 x 10(11) cm-2.