Temperature and Composition of Titan's Upper Atmosphere

We re-examine the energy balance of Titan's upper atmosphere in light of the recent results on composition and temperature from an analysis of Voyager UVS occultation results. The hypothesis that the thermal structure is controlled by the balance between solar EUV heating and radiative cooling by HCN will be tested by comparison of thermal structure models with measured temperatures. The relevance for anticipated Cassini data will also be discussed.