The floatability of aerosols and wave damping on Titan’s seas
Résumé
Titan, the enigmatic large moon of Saturn, is unique because it is the only satellite of the solar system that is surrounded by a dense atmosphere. Thick layers of photochemical organic aerosols shroud the surface and sediment to the ground. In polar regions, large lakes and seas of liquid hydrocarbons were discovered by the Cassini–Huygens mission. Aerosols that sediment above the lakes run into a liquid surface in which new interactions can take place. In this paper, we address the question of the first contact between the aerosols and the lakes: do the aerosol particles float or rapidly sink into the lakes? We investigated the possible effects of a floating film or slick formed by this organic material and other products of the atmosphere. We also compared the wave damping effect on Earth's oceans to the Titan counterparts. According to this work, Titan appears to be a much more favourable place for such a damping. By inhibiting the formation of the first ripples, this phenomenon could impede the existence of waves at wavelengths larger than a few centimetres. This effect could explain the remarkable smoothness of the sea surface often noticed in Cassini observations.