AIMS · Analogue Icy Moon Simulations

Icy moons with subsurface oceans in the outer solar are prime targets in the search for extraterrestrial life. Among these bodies, the subsurface ocean of Saturn’s moon Enceladus has a high astrobiological potential. From south polar fissures in its icy crust, Enceladus expels previously dissolved and suspended subsurface ocean material into space in the form of ice grains and plume gas. Until 2017, before the end of the space mission, mass spectrometers aboard the Cassini-Huygens spacecraft orbiting Saturn sampled and analyzed Enceladus subsurface material during several flybys. The analysis of Cassini’s mass spectrometer data obtained from the plume material suggested a diverse inventory of chemical species of biological interest. With AIMS, I will explore the habitability of Enceladus’ subsurface ocean by simulating the geochemical aqueous synthesis and alteration of chemical species under subsurface geophysical conditions relevant to Enceladus. The proposed simulations will thus track the chemical evolution of species during their ascent through the ocean from the moon’s hydrothermally-active rocky core in order to further constrain interpretations and provide new insights into Cassini data and also provide additional feedback and guidance for future space missions to Enceladus. The AIMS-research would be accomplished with two interrelated but operationally independent experiments: (i) hydrothermal (HT) reactor & (ii) ocean-evolution (OE) reactor, to simulate subsurface geo-chemical and -physical processes in the core, ocean and icy vent. This will advance our understanding of synthesis, degradation, alteration, and evolution of organic, inorganic and also biogenic material before it would incorporate into ice grains or plume gas. The results from AIMS research could be used to further constraint subsurface geophysicochemical models to explore the habitability of Enceladus and also to extrapolate to future missions towards other icy moons.