Effect of high pressure on organic chemistry in large ocean worlds

Objective

The presence of water in its liquid state is thought to have driven Earth's prebiotic chemistry and is considered an essential element for the emergence of life. This explains the unprecedented interest in extraterrestrial ocean worlds harboring liquid oceans underneath their icy crusts. Despite advanced space mission programs and interdisciplinary research to assess the habitability of ocean worlds, the question of the emergence of life is mostly addressed through the prism of the Earth’s contexts. High pressure is a parameter that makes a major difference between the hydrospheres of Earth and large ocean worlds. While various volatile organics are present in extra-terrestrial hydrospheres and can potentially act as biological precursors, information on their chemical evolution at relevant pressure-temperature-composition conditions in aqueous environment is almost absent. The project OCEAN is designed to cover this gap of knowledge. My team will use advanced in situ X-Ray and neutron diffraction techniques in combination with Raman and infrared spectroscopy to investigate processes that control the evolution of organic volatile compounds in interiors of ocean worlds, from interaction of water with simple molecules to formation of more complex prebiotic organic molecules. At various conditions, we will define structural properties, equations of state and phase stabilities of solid organic compounds. OCEAN will allow us 1) to formulate fundamental laws correlating the chemical nature of organic precursors and their pressure-induced transformation pathways in aqueous environment and 2) to understand organics transport and chemical exchange between the interiors and surfaces of large ocean worlds. In combination with a created database of infrared spectra of organic-bearing frozen mixtures, OCEAN will provide a critical reference for interpretation of upcoming compositional data from the space missions and for accessing the astrobiological potential of ocean worlds.