82-3 Geochemistry of Titan's Lakes and Seas

Session: Friends of Hoth, Episode IX: The Rise of Icy Ocean Worlds

Presenting Author:

Jennifer Hanley

Authors:

Hanley, Jennifer¹, Thieberger, Cece², Engle, Anna³, O'Brien, Oliver⁴, Tan, Sugata⁵, Lindberg, Gerrick⁶, Brand, Marlee⁷, Grundy, Will⁸, Steckloff, Jordan⁹, Tegler, Steve¹⁰

(1) Lowell Observatory, Flagstaff, AZ, USA; Northern Arizona University, Flagstaff, AZ, USA, (2) Northern Arizona University, Flagstaff, AZ, USA; Lowell Observatory, Flagstaff, AZ, USA, (3) Northern Arizona University, Flagstaff, AZ, USA; Lowell Observatory, Flagstaff, AZ, USA, (4) University of Maryland, College Park, MD, USA; Lowell Observatory, Flagstaff, AZ, USA, (5) Planetary Science Institute, Tucson, AZ, USA, (6) Northern Arizona University, Flagstaff, AZ, USA, (7) Northern Arizona University, Flagstaff, AZ, USA, (8) Lowell Observatory, Flagstaff, AZ, USA; Northern Arizona University, Flagstaff, AZ, USA, (9) Planetary Science Institute, Tucson, AZ, USA, (10) Northern Arizona University, Flagstaff, AZ, USA,

Abstract:

Titan is the only extraterrestrial environment known to support bodies of standing liquid on its surface. The Cassini mission provided important composition measurements of a few lakes and seas, which indicate a mixture of methane and ethane liquids, in addition to dissolved nitrogen from the atmosphere. Cassini also measured trace amounts of higher-order hydrocarbons in Titan’s atmosphere. When these trace species fall down onto the surface and mix with the lakes and seas, they create unique chemical conditions and alter the phase behavior, solubility, and stability of Titan’s surface liquids. In an effort to study these environments, we present our experimental work done in the Astrophysical Materials Lab at Northern Arizona University (NAU). To date, we have studied methane-ethane-nitrogen stability, as well as three different trace species (propane, ethylene, and acetylene) in methane-ethane mixtures under a nitrogen atmosphere of 1.5 bar to replicate Titan lakes. Specifically, we incorporated 1-10% additions of a given trace species to the methane-ethane-nitrogen system and performed cooling and warming cycles of our sample between 70 - 100 K. Through a combination of visual inspection and Raman spectroscopy, we found that these mixtures undergo phase changes at different temperatures than their individual end members. The observed phase changes under these conditions have exciting implications for Titan’s lakes and seas, including compositional stratification of surface liquids, bubbles, ice formation, and other multiphase equilibria. We will present the results of these experiments, in addition to thermodynamic models and how they relate to Titan environments.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-11356

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.