Experimental study of ethylene evaporites under titan conditions

by Czaplinski, Ellen C.; Gilbertson, Woodrow A.; Farnsworth, Kendra K.; Chevrier, Vincent F.

Titan has an abundance of lakes and seas, as confirmed by Cassini. Major components of these liquid bodies include methane (CH4) and ethane (C2H6), however, evidence indicates that minor components such as ethylene (C2H4) may also exist in the lakes. As the lake levels drop, 5- µm-bright deposits, resembling evaporite deposits on Earth, are left behind. Here, we provide saturation values, evaporation rates, and constraints on ethylene evaporite formation by using a Titan simulation chamber capable of reproducing Titan surface conditions (89 - 94 K, 1.5 bar N2). Exptl. samples were analyzed using FTIR (Fourier-Transform IR) spectroscopy, mass, and temperature readings. Ethylene evaporites form more quickly in a methane solvent than an ethane solvent, or a mixture of methane/ethane. We measured an average evaporation rate of (2.8 ± 0.3) x 10-4 kgm-2s-1 for methane, and an average upper limit evaporation rate of < 5.5 x 10-6 kgm-2s-1 for ethane. Addnl., we observed red shifts in ethylene absorption bands at 1.630 µm and 2.121 µm, and the persistence of a methane band at 1.666 µm.

arXiv.org, e-Print Archive, Astrophysics
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