Dr. Devan Nisson investigates the geochemistry and microbiology of deep subsurface brine systems. She has utilized aqueous geochemical modeling programs (including Geochemist’s Workbench) alongside water/rock isotopic measurement and mass-balance techniques to model brine formation history over geologic time, and how biotic vs abiotic (e.g. water-rock interaction) processes influence microbial habitability. Dr. Nisson completed a PhD in the Geosciences Department at Princeton University in 2023 (advisors: T.C. Onstott, Bess Ward) where she examined the influence of water radiolysis over Ga timescales on H2/oxidant production, brine salinity formation, and single cell genomics stress-response features in Moab Khotsong gold and uranium mine of the Witwatersrand Basin, South Africa. This work not only elucidates the limits of life in extreme environments of the terrestrial subsurface, but provides invaluable information regarding microbial habitability constraints in potentially similar planetary brine systems. Dr. Nisson is additionally a collaborating member of the Origin’s and Habitability Lab at the Jet Propulsion Laboratory in Pasadena, CA where she has worked with Dr. Scott Perl since 2020 to apply microbial maintenance energy models and brine formation models to putative planetary brine systems on Mars and beyond. Prior to her work at Princeton, Dr. Nisson completed her BS in Ecology and Evolutionary Biology from UC Irvine (advisor: Dr. Steven Allison) where she considered leaf-litter inhabiting microbial metabolic stress response to drought via extracellular enzyme degradation activities.