Thermodynamics in an icy world: The atmosphere and internal structure of Saturn's moon Titan

Abstract

Thermodynamic principles can be applied for describing the atmospheres and the internal structure of celestial bodies using Saturn's moon Titan as a most appropriate example.Some basic physical data of Titan such as the measured temperature and pressure on its surface, the atmospheric composition, Titan's density and diameter, and other information allow us to predict further properties which have not been determined directly by measurements. The existence of a liquid phase covering smaller parts of the surface can be confirmed, and the composition of the liquid can be predicted. The change of temperature with the height over the surface and the appearance of clouds and rainfall in the atmosphere consisting essentially of CH 4 + N 2 mixtures can also be predicted. By developing a new method of calculation of atmospheric scenarios, the chemical history of Titan's surface and atmosphere can be roughly reconstructed taking into account the known rate of methane destruction caused by radiative absorption of sunlight. Finally, some estimations concerning the material structure and the pressure behavior of Titan's interior can be made. Only basic knowledge of thermodynamics and physics is required to understand essential features in a strange world that is more than one billion kilometers away from us.

Dissolution on Titan and on Earth: Toward the age of Titan's karstic landscapes

“…On one hand, the general lack of unequivocal cryovolcanic features on Titan tends to limit the likelihood of the cryovolcanic hypothesis (Moore and Pappalardo, 2011). A methane-based permafrost would be difficult to form on Titan due to the presence of nitrogen in the atmosphere (Lorenz and Lunine, 2002;Heintz and Bich, 2009). Its putative cyclic destabilization would also be challenging, given the tiny temperature variations between summer and winter, day and night, equator and poles (Jennings et al, 2009;Lora et al, 2011;Cottini et al, 2012) over all timescales (Aharonson et al, 2009;Lora et al, 2011).…”

Intermolecular potential energy surface and thermophysical properties of the CH4–N2 system

“…Nitrogen and methane are the a) Electronic mail: robert.hellmann@uni-rostock.de main constituents of Titan's atmosphere, and the dynamic interaction between the lakes and the atmosphere is currently of special interest. [12][13][14][15][16] Natural gas, which is predominantly methane, also contains nitrogen, which not only reduces its calorific value, but plays an important part in the liquefaction process.…”