Cassini finds molecular hydrogen in the Enceladus plume: Evidence for hydrothermal processes

2017/04/13 by J. H. Waite, Christopher R. Glein, R. Perryman +10 · 9 citations
Physics and Astronomy · Chemistry · #Astro and Planetary Science #Planetary Science and Exploration #Astrophysics and Star Formation Studies #Enceladus #Hydrothermal circulation #Plume #Astrobiology #Hydrothermal vent #Hydrogen molecule #Hydrogen #Earth science #Chemistry #Geology #Physics #Paleontology #Meteorology

paper · doi:10.1126/science.aai8703

openalex publication_date 2017/04/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

Hydrothermal processes on Enceladus Saturn's moon Enceladus has a subsurface ocean covered by a layer of ice. Some liquid escapes into space through cracks in the ice, which is the source of one of Saturn's rings. In October 2015, the Cassini spacecraft flew directly through the plume of escaping material and sampled its chemical composition. Waite et al. found that the plume contains molecular hydrogen, H 2 , a sign that the water in Enceladus' ocean is reacting with rocks through hydrothermal processes (see the Perspective by Seewald). This drives the ocean out of chemical equilibrium, in a similar way to water around Earth's hydrothermal vents, potentially providing a source of chemical energy. Science , this issue p. 155 ; see also p. 132

Citations

• A salt-water reservoir as the source of a compositionally stratified plume on Enceladus
• Cassini Encounters Enceladus: Background and the Discovery of a South Polar Hot Spot
• The pH of Enceladus’ ocean
• Ongoing hydrothermal activities within Enceladus
• Solar System Abundances and Condensation Temperatures of the Elements
• Composition and Physical Properties of Enceladus' Surface
• Cassini Ion and Neutral Mass Spectrometer: Enceladus Plume Composition and Structure
• Liquid water on Enceladus from observations of ammonia and 40Ar in the plume
• H 2 -rich fluids from serpentinization: Geochemical and biotic implications
• Measurement of the diffusion coefficients of sparingly soluble gases in water

Cited by

• Macromolecular organic compounds from the depths of Enceladus
• The subsurface habitability of small, icy exomoons
• Bayesian analysis of Enceladus’s plume data to assess methanogenesis
• Coexistence of CH4, CO2, and H2O in exoplanet atmospheres
• The Emergence of Life
• Special Cases: Moons, Rings, Comets, and Trojans
• A pole-to-equator ocean overturning circulation on Enceladus
• Biological methane production under putative Enceladus-like conditions
• Enceladus [wikipedia]

Related

• Enceladus' hot springs
• The pH of Enceladus’ ocean
• JWST molecular mapping and characterization of Enceladus' water plume feeding its torus
• Enceladus: An Active Ice World in the Saturn System
• Differing Enceladean ocean circulation and ice shell geometries driven by tidal heating in the ice versus the core