Does ice float in Titan's lakes and seas?

► Titan's lakes and seas are modeled as methane-ethane-nitrogen systems and the densities of the liquid and solid phases are calculated. ► For some compositions and temperatures, ice formed from freezing will float. ► Considering reasonable porosities in the solid phase broadens the conditions that result in floating hydrocarbon ices. ► For a restricted range of compositions, the lakes and seas can simultaneously have ice that floats and sinks.