Europa may be lifeless and uninhabitable, study says

A Nature Communications paper led by Paul Byrne reports that models of Europa's seafloor show little to no active faulting today, which would limit the formation of hydrothermal vents and the chemical energy such vents provide; NASA's Europa Clipper and ESA's JUICE missions will gather further observations to clarify the moon's interior.

Europa is an ice-covered moon with a global ocean and long has been a leading target in the search for life because it likely has water, heat, and chemical ingredients. New research published in Nature Communications and led by Paul Byrne models the strength and behavior of Europa's seafloor and the forces that could drive faulting there. The authors report that current tidal and internal processes are unlikely to produce the deep, active faulting thought necessary for sustained hydrothermal venting. That conclusion challenges a key mechanism proposed to supply chemical energy for life beneath Europa's ocean. Key findings: - The study models possible drivers of seafloor faulting on Europa, including tidal flexing, global contraction, mantle convection, and serpentinization, and finds them insufficient to produce deep, ongoing fault activity today. - Without active seafloor faulting, the models imply limited formation of deep hydrothermal vents that on Earth support chemoautotrophic ecosystems by providing reduced chemical energy. - Some observed surface plumes may originate from pockets in the ice rather than from the deep ocean, a possibility that reduces the need for seafloor venting to explain those observations. - NASA's Europa Clipper and ESA's JUICE missions are expected to collect more focused data on Europa's ice shell, ocean thickness, and surface features to reduce current uncertainties. Summary: The paper narrows the likelihood that Europa's present seafloor hosts the kind of deep, active hydrothermal systems that would supply sustained chemical energy for life, based on current models of driving forces and rock strength. Upcoming measurements from Europa Clipper and JUICE should provide more direct constraints on the moon's ice and ocean structure and help clarify whether alternate energy sources exist; Undetermined at this time.