Enceladus’ plumes reveal a hydrogen-powered hidden ocean

Saturn’s moon Enceladus vents a subsurface ocean through its south-pole tiger stripes, and Cassini measurements show hydrogen in the plume, likely produced by water-rock reactions in the ocean (serpentinisation) that energy-hungry microbes could exploit as in Earth's hydrothermal vents. New analyses find a broader suite of organic compounds and phosphates in plume grains, bringing five of the six bio-essential elements to the scene, but no life is detected and sulfur remains elusive. The results strengthen the case for habitability and set the stage for a future mission to search for signs of biology rather than a new discovery of life itself.