There is growing evidence that heavy organic molecules are a major component of the outer solar system bodies such as icy moons, asteroides, comets, and Trans-Neptunian Objects (TNOs). Density profiles inferred from measurements of space missions require a low-density component in the core of the largest objects such as Ganymede and Titan. These observations suggest that a previously overlooked low-density component, identified as carbonaceous organic matter (COM), is one of the three main components, in addition to ice and rocks, building planetary bodies that formed beyond the ice line. However, there is a dearth of laboratory experiments and numerical simulations exploring the interaction of the heavy organic molecules constituting the COM with both the ice component (mainly H2O ices) and the rocky component (hydrated silicates, oxides and sulphides) at pressures relevant to icy moons.
How does the presence of COM affect the thermal and chemical evolution of ocean worlds? The interaction between COM, ice and rocks is therefore essential for understanding the evolution of ocean worlds and for assessing their habitability potential. First, this project conducts laboratory experiments using two types of high-pressure devices: diamond anvil cells (DAC) coupled with in situ Raman spectroscopy or X-ray diffractometer, and Internally Heated Pressure Vessels (IHPV) that allow the characterization of the products by Gas Chromatography for the gas phase and FT-ICR MS for the organic phase. Second, it develops a thermochemical evolution model that can handle the chemical reactions and the thermo-chemical properties of the three components. Third, it applies the results to the evolution of ocean worlds in our solar system and beyond.
