Pluto’s Secret Sauce: Do Subsurface Volatile Fluids Shape Its Geology?

Co-I Dr. Sugata Tan will apply CRYOCHEM 2.0 equation of state (EOS) to describe the multiphase equilibria of binary and ternary systems containing nitrogen (N2), carbon monoxide (CO), and methane (CH4) at conditions relevant to Pluto’s subsurface. To evaluate possible phases that are involved in the equilibrium of the ternary mixture, calculations on the constituting binary mixtures are also needed. Such calculations will be made for EOS validation, where predictions using the current EOS parameters prior to experiments will be needed to help with design on measurement conditions that allow effective experiments, which eventually will provide feedback towards higher accuracy by further fine-tuning the parameters if deemed necessary.

The resulting validated CRYOCHEM will be applied to support the team with relevant equilibrium limiting cases in their models. In the molecular dynamics modeling on fluid viscosity by another Co-I, it will also be useful for calculating fluid densities for comparison purposes.

Co-I Dr. Jordan Steckloff has considerable experience modeling planetary physics problems and developed the TITANPOOL numerical model to study the behavior of liquid bodies on Titan, and in fitting these material properties to empirical equations. Dr. Steckloff will create empirical fits to laboratory and simulation data, for use in codes that require a fast, reasonably accurate EOS. Dr. Steckloff will aid Co-Is in including these fits in their work.

Drs. Tan and Steckloff will contribute to all publications resulting from this work. For all these efforts, we budget more or less 8 weeks/year of effort in all years as listed in the proposed budget.