The cold chemistry of cryovolcanism: Insights from experimental and natural analogs

Mark Fox-Powell Open University

‘Cryovolcanism’ at icy worlds offers immense promise for astrobiology, as it appears to transport material from habitable subsurface oceans to surface environments, where it can be studied by spacecraft. Because of this promise, cryovolcanic systems, whether active as in the case of the plumes of Enceladus, or historic as indicated by geologic evidence at Europa and elsewhere, continue to be a major focus for icy worlds exploration. However, using cryovolcanic materials to probe the habitability of subsurface oceans depends on understanding how the composition of erupted materials could be changed by the eruptive processes themselves. I will present results from experimental and natural systems exploring the potential chemical diversity generated by cryovolcanism. I will show how composition and structure of erupted salty ices can provide a record of their thermal history that could be used to identify cryovolcanic deposits and reconstruct cryovolcanic processes. I will also highlight how terrestrial geysers and cold brine seeps can help us understand how ocean composition and evidence of life could be expressed in cryovolcanic systems. Finally, I will discuss the relevance of our results for understanding the findings of existing and upcoming missions.