The surface energy balance at the Huygens landing site and the moist surface conditions on Titan

► The Huygens probe encountered moist surface conditions on Titan. ► Proper surface moisture models for Titan must include ternary solutions. ► We model the moist surface conditions of Titan over diurnal and seasonal timescales. ► We quantify the surface energy budget. ► We find that the surface moisture is probably a remnant from a recent rainfall.