Hydrothermal co-alteration of organic material with minerals and ammonia in chondrite parent bodies and Enceladus

Secondary processes on the planetesimals or planetary bodies are perhaps mainly responsible for organics' diversity in the solar system. The Cassini spacecraft's analyses of Enceladus' vapor plumes identified the presence of organic matter (OM) and NH₃, as well as hydrogen and nanosilicate particles that indicate potentially active hydrothermal mineral alteration. Although this result evokes active organic-mineral interactions to the present, the satellite studies are limited to identifying a few select compounds. In comparison, lab studies of meteorite soluble organic matter (SOM) detected more than 10,000 peaks in mass spectra, including OM essential for life. Furthermore, such OM in abundance that varies depending on the rocks' hydrothermal alteration degree. This indicates that hydrothermal co-alteration of OM with minerals and nitrogen species in rocky hosts may be critical to development of the amino acids and other complex OM. Although lab study can reveal details of OM compositions, chondrites are all altered. Therefore, using simulants is crucial to reveal the mineral-organic interactions, the influence of NH₃, and OM evolutions in the planetary and undifferentiated bodies. We designed hydrothermal experiments of OM alteration with and without the presence of 1) a reference mineral, olivine, and 2) NH₃. The solid OM was combined with olivine (50-125 µm) and a 0.5 mol liquid NH₃ solution under argon and reacted in gold capsules for 30 days at 100⁰C. As initial materials, we used a complex solid OM synthesized by ionizing a carbon- and hydrogen- gas source in a Nebulotron instrument (at CRPG in Nancy). Before the hydrothermal experiments, we analyzed the Nebulotron SOM extract by the high-resolution mass spectrometer, Orbitrap. We confirmed the presence of coherent CH₂-polymerization patterns that were observed in the previous study. We plan to report what the mineral-rock interactions change the distribution of complex OM.