Enceladus tests whether habitability guarantees life

Enceladus hosts a global ocean with water–rock chemistry, energy sources and a rich organic inventory, making it plausibly habitable over geological ages. But a search for life via plume sampling would need to be comprehensive and sensitive; a negative result could still be scientifically meaningful by bounding the circumstances under which life arises, demonstrating that habitability and abiogenesis are not the same.