Exploring underwater vent systems: New technologies and strategies to advance life detection and scientific understanding of ocean worlds

Hydrothermal vents are some of the most exciting candidates for habitable environments on Ocean Worlds, because they supply reduced chemical substrates that enable the development of diverse biological communities capable of harnessing energy from ambient redox gradients. To characterize the habitability of a hydrothermally active region, it is necessary to not only compare different vent sites in the same area, but to monitor them over time with high frequency techniques that can capture the episodic nature of geochemical and metabolic changes. In response, we have developed the In-situ Vent Analysis Divebot for Exobiology Research (InVADER) concept, a tightly integrated imaging and laser Raman spectroscopy/laser-induced breakdown spectroscopy/laser induced native fluorescence (LRS/LIBS/LINF) instrument capable of in-situ, rapid, long-term underwater analyses of vent fluid and precipitates. Such analyses will be critical for finding and studying life and life's precursors at vent systems on Ocean Worlds. InVADER allows, for the first time, in-situ, autonomous, non-destructive measurements of a) relevant disequilibria in vent systems, b) composition and mineralogy of hydrothermal chimneys and associated precipitates, c) relevant small-scale features that are indicators of vent geochemistry and/or habitability, and d) the presence and distribution of organics and biomass. Further, single observations or sampling do not capture the dynamic nature of hydrothermal vent systems which can undergo significant changes over short periods of time; a system capable of continuous monitoring over longer time periods (yet able to conduct high-frequency measurements) is required. InVADER fills these gaps, and advances readiness in vent exploration on Earth and ocean worlds by simplifying operational strategies for identifying and characterizing submarine vents. We have studied natural black smoker chimney sample materials using InVADER precursor technologies. The synergistic use of microimaging and LRS/LIBS/LINF determined the presence of sphalerite, isocubanite, chalcopyrite, and other polymetallic sulfides as well as sulfur, anhydrite, gypsum, and organic material. Our data underline the tremendous value of combined LRS/LIBS/LINF for astrobiological investigations of vent systems