What key ingredient essential for terrestrial life formation is confirmed to be cycling into the liquid water on Enceladus?

Carbon-based compounds and other essential organic molecules

The habitability assessment for Enceladus relies on finding not just water, but water interacting with the necessary chemical building blocks. The analysis of plume material confirmed the presence of simple organic molecules, carbon dioxide, and molecular hydrogen. The text emphasizes that finding liquid water actively interacting with rock—which facilitates energy transfer—is critical, but finding that water actively cycling carbon-based compounds into the mix is the next crucial step. This active cycling provides the necessary raw material for forming the basic building blocks of biological molecules, moving the environment beyond simply having water ice to possessing a chemically rich, dynamic system.