Water-Rock Reactions on Earth and Mars: Insights from Remote Sensing, Meteorites, and Subsurface ExplorationTarnas, Jesse DylancreatorMustard, JohnAdvisorOrphan, VictoriaReaderMilliken, RalphReaderLiang, YanReaderParman, StephenReaderBrown University. Department of Earth, Environmental, and Planetary Sciencessponsor2020xxii, 406 p.born digitalThesis (Ph. D.)--Brown University, 2020thesesWater-rock reactions affect the evolution of planetary crusts and largely control their potential for habitability and biosignature preservation. Here we use data from remote sensing instruments, martian meteorites, and subsurface exploration on Earth to evaluate geochemical controls on Earth's subsurface habitability, the potential for habitable subsurface environments on Mars, and possible locations of biosignature preservation on Mars. The results presented here demonstrate that water-rock-gas reactions produce a wide diversity of geochemical conditions in Earth's subsurface. They also demonstrate that the subsurface of Mars is likely habitable for Earth-like life from a redox-energy perspective. In addition, advanced hyperspectral image analysis techniques are tested in the laboratory and applied to orbital hyperspectral data of Mars to detect hydrated silica and Al-phyllosilicate in Jezero crater. Hydrated silica in Jezero crater is a worthy target for investigation by NASA's Perseverance rover due to its high biosignature preservation potential. In concert, the results from this dissertation aid the search for extinct and extant extraterrestrial life in the Solar System.SpectroscopyGeochemistryRemote sensingMars (Planet)Planetary sciencehabitabilitysubsurfaceExobiologyEarth (Planet)EnglishRPB20210607dissertations