{ "note": "Per-body water inventory — every form water takes (ice · subsurface ocean · brine · vapour · hydrated mineral · adsorbed · supercritical), with Titan's hydrocarbon seas flagged as non-water. Cited, confidence-tagged; NATURAL/PROCESSED, kept out of the baked tree. Summaries give catalogued volume, % of Earth's ocean, and the surface/subsurface split (volumes are partial — a floor, never invented).", "generatedAt": "2026-06-16", "earthOceanKm3": 1335000000, "bodies": 20, "reservoirs": 36, "byPhase": { "ice": 12, "subsurface_ocean": 8, "hydrated_mineral": 5, "vapour": 4, "brine": 3, "supercritical": 2, "adsorbed": 1, "hydrocarbon_liquid": 1 }, "summaries": { "EARTH": { "reservoirs": 2, "phases": [ "subsurface_ocean", "ice" ], "catalogedKm3": 1361000000, "pctEarthOcean": 101.94756554307116, "surfaceKm3": 1361000000, "subsurfaceKm3": 0 }, "MERCURY": { "reservoirs": 1, "phases": [ "ice" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "MOON": { "reservoirs": 4, "phases": [ "ice", "adsorbed" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "MARS": { "reservoirs": 5, "phases": [ "ice", "hydrated_mineral", "brine" ], "catalogedKm3": 2420000, "pctEarthOcean": 0.18127340823970037, "surfaceKm3": 2420000, "subsurfaceKm3": 0 }, "CERES": { "reservoirs": 4, "phases": [ "brine", "hydrated_mineral", "ice", "vapour" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "VESTA": { "reservoirs": 1, "phases": [ "hydrated_mineral" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "BENNU": { "reservoirs": 2, "phases": [ "hydrated_mineral", "brine" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "RYUGU": { "reservoirs": 1, "phases": [ "hydrated_mineral" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "EUROPA": { "reservoirs": 2, "phases": [ "subsurface_ocean", "ice" ], "catalogedKm3": 3000000000, "pctEarthOcean": 224.7191011235955, "surfaceKm3": 0, "subsurfaceKm3": 3000000000 }, "GANYMEDE": { "reservoirs": 1, "phases": [ "subsurface_ocean" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "CALLISTO": { "reservoirs": 1, "phases": [ "subsurface_ocean" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "ENCELADUS": { "reservoirs": 2, "phases": [ "subsurface_ocean", "vapour" ], "catalogedKm3": 26000000, "pctEarthOcean": 1.9475655430711611, "surfaceKm3": 0, "subsurfaceKm3": 26000000 }, "TITAN": { "reservoirs": 1, "phases": [ "subsurface_ocean" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "TRITON": { "reservoirs": 1, "phases": [ "subsurface_ocean" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "PLUTO": { "reservoirs": 2, "phases": [ "subsurface_ocean", "ice" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "CHARON": { "reservoirs": 1, "phases": [ "ice" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "JUPITER": { "reservoirs": 1, "phases": [ "vapour" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "SATURN": { "reservoirs": 1, "phases": [ "vapour" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "URANUS": { "reservoirs": 1, "phases": [ "supercritical" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 }, "NEPTUNE": { "reservoirs": 1, "phases": [ "supercritical" ], "catalogedKm3": null, "pctEarthOcean": null, "surfaceKm3": 0, "subsurfaceKm3": 0 } }, "table": { "EARTH": [ { "phase": "subsurface_ocean", "where": "surface oceans (the reference reservoir)", "amount": "1.335×10⁹ km³", "volumeKm3": 1335000000, "deep": false, "confidence": "confirmed", "source": "Charette & Smith 2010, Oceanography" }, { "phase": "ice", "where": "polar caps + glaciers", "amount": "~2.6×10⁷ km³", "volumeKm3": 26000000, "confidence": "confirmed", "source": "Vaughan et al. 2013, IPCC AR5 Ch.4 (cryosphere)" } ], "MERCURY": [ { "phase": "ice", "where": "permanently shadowed polar craters (buried under a dark lag)", "amount": "2×10¹⁶–10¹⁸ g", "confidence": "confirmed", "source": "Lawrence et al. 2013, Science (MESSENGER neutron spectrometer)" } ], "MOON": [ { "phase": "ice", "where": "permanently shadowed polar craters (Cabeus)", "amount": "5.6 ± 2.9 wt% in the impact regolith; 155 ± 12 kg in the LCROSS plume", "confidence": "confirmed", "source": "Colaprete et al. 2010, Science (LCROSS)" }, { "phase": "ice", "where": "surface-exposed ice in polar PSRs", "confidence": "confirmed", "source": "Li et al. 2018, PNAS (Chandrayaan-1 M³)" }, { "phase": "adsorbed", "where": "sunlit regolith — OH/H₂O veneer, increasing poleward", "amount": "tens–~400 ppm (Clavius 100–412 ppm)", "confidence": "confirmed", "source": "Li & Milliken 2017, Sci. Adv.; Honniball et al. 2020, Nat. Astron. (SOFIA)" }, { "phase": "ice", "where": "bulk polar near-surface hydrogen", "amount": "~11–330 Mt (model-dependent)", "confidence": "inferred", "source": "Feldman et al. 1998 (Lunar Prospector); Lawrence et al. 2016, Icarus" } ], "MARS": [ { "phase": "ice", "where": "south polar layered deposits (Planum Australe)", "amount": "~1.6×10⁶ km³ ≈ 11 m global layer", "volumeKm3": 1600000, "confidence": "confirmed", "source": "Plaut et al. 2007, Science (Mars Express MARSIS)" }, { "phase": "ice", "where": "north polar layered deposits (Planum Boreum)", "amount": "~8.2×10⁵ km³ ≈ 1.5 m global layer", "volumeKm3": 820000, "confidence": "confirmed", "source": "Putzig et al. 2009, Icarus (MRO SHARAD)" }, { "phase": "ice", "where": "buried mid-latitude ground ice (Arcadia, Deuteronilus)", "amount": "shallow, widespread (1–>5 m depth)", "deep": true, "confidence": "inferred", "source": "Morgan et al. 2021, Nat. Astron. (SWIM)" }, { "phase": "hydrated_mineral", "where": "ancient terrains — phyllosilicates (clays), sulfates, opaline silica", "amount": "ocean-scale bound inventory (~100–1500 m GEL sequestered)", "confidence": "confirmed", "source": "Bibring et al. 2006; Mustard et al. 2008; Scheller et al. 2021, Science" }, { "phase": "brine", "where": "proposed deep south-polar subglacial brine (~1.5 km)", "confidence": "contested", "source": "Orosei et al. 2018, Science — challenged by clay/rock reinterpretations (2021–2025)" } ], "CERES": [ { "phase": "brine", "where": "deep brine reservoir feeding the Occator faculae (~40 km)", "confidence": "inferred", "source": "Raymond et al. 2020, Nat. Astron. (Dawn gravity)" }, { "phase": "hydrated_mineral", "where": "hydrohalite (NaCl·2H₂O), Na-carbonate, ammonium chloride at the faculae", "confidence": "confirmed", "source": "De Sanctis et al. 2020, Nat. Astron. (Dawn VIR)" }, { "phase": "ice", "where": "ice-rich crust + shallow regolith ice table", "amount": "17–29 wt% water-equivalent H (GRaND); crust ~90→0 vol% ice over ~117 km (model)", "confidence": "confirmed", "source": "Prettyman et al. 2017, Science (Dawn GRaND); Pamerleau et al. 2024, Nat. Astron." }, { "phase": "vapour", "where": "localised mid-latitude exosphere", "amount": "~6 kg/s", "confidence": "confirmed", "source": "Küppers et al. 2014, Nature (Herschel HIFI)" } ], "VESTA": [ { "phase": "hydrated_mineral", "where": "OH in EXOGENIC hydrated material (CM-impactor delivered) — a genuinely dry body", "amount": "~400 ppm H (regional)", "confidence": "confirmed", "source": "De Sanctis et al. 2012, ApJL; Prettyman et al. 2012, Science (Dawn)" } ], "BENNU": [ { "phase": "hydrated_mineral", "where": "global hydrated clays (Mg-serpentine + smectite); returned sample ~80 vol% phyllosilicate", "amount": "~0.7 wt% H (surface)", "confidence": "confirmed", "source": "Hamilton et al. 2019, Nat. Astron.; Lauretta et al. 2024 (OSIRIS-REx sample)" }, { "phase": "brine", "where": "evaporite sequence (Na-phosphates/carbonates) from an ancient parent-body brine", "confidence": "inferred", "source": "McCoy et al. 2025, Nature (OSIRIS-REx sample)" } ], "RYUGU": [ { "phase": "hydrated_mineral", "where": "ubiquitous hydrated phyllosilicates (CI-like); CO₂-bearing fluid inclusion in pyrrhotite", "amount": "parent body ~20–30 wt% water", "confidence": "confirmed", "source": "Kitazato et al. 2019, Science (Hayabusa2); Nakamura/Yokoyama et al. 2022–23 (sample)" } ], "EUROPA": [ { "phase": "subsurface_ocean", "where": "global salt-water ocean beneath a 15–25 km ice shell", "amount": "~3×10⁹ km³ (≈ 2–3× Earth oceans)", "volumeKm3": 3000000000, "confidence": "confirmed", "source": "Kivelson et al. 2000, Science; Khurana et al. 1998, Nature (Galileo induction)" }, { "phase": "ice", "where": "water-ice crust; endogenous CO₂; transient vapour plumes (intermittent)", "confidence": "confirmed", "source": "Villanueva et al. 2023, Science (JWST CO₂; no plume that epoch)" } ], "GANYMEDE": [ { "phase": "subsurface_ocean", "where": "salty ocean (~100 km thick) under a ~150 km ice crust — likely the largest moon ocean", "confidence": "inferred", "source": "Saur et al. 2015, JGR (Hubble auroral oscillation); Galileo induction" } ], "CALLISTO": [ { "phase": "subsurface_ocean", "where": "possible salty ocean at depth (ionosphere ambiguity)", "confidence": "contested", "source": "Zimmer et al. 2000, Icarus; Cochrane et al. 2025, AGU Adv." } ], "ENCELADUS": [ { "phase": "subsurface_ocean", "where": "global ocean (~40 km deep) over a rocky core; hydrothermal", "amount": "~25–27×10⁶ km³", "volumeKm3": 26000000, "confidence": "confirmed", "source": "Thomas et al. 2016, Icarus (libration); Čadek et al. 2016, GRL" }, { "phase": "vapour", "where": "south-polar plumes (H₂O + ice grains, salts, silica, H₂, phosphates)", "confidence": "confirmed", "source": "Porco et al. 2006; Waite et al. 2017, Science; Postberg et al. 2023, Nature" } ], "TITAN": [ { "phase": "subsurface_ocean", "where": "ammonia-rich water ocean beneath a ~50 km ice shell (~250 km deep)", "confidence": "inferred", "source": "Iess et al. 2012, Science (Cassini tides)" }, { "phase": "hydrocarbon_liquid", "where": "SURFACE polar seas (Kraken/Ligeia/Punga) — liquid methane/ethane, NOT water", "amount": ">1.6×10⁶ km² (~2% of surface); Ligeia ~160 m deep", "confidence": "confirmed", "source": "Mastrogiuseppe et al. 2014, GRL (Cassini RADAR)" } ], "TRITON": [ { "phase": "subsurface_ocean", "where": "possible interior ocean; surface N₂/CH₄/CO/H₂O ice; nitrogen-driven plumes", "confidence": "contested", "source": "Smith et al. 1989, Science (Voyager 2); Hendrix et al. 2021, PSJ" } ], "PLUTO": [ { "phase": "subsurface_ocean", "where": "possible ammonia-rich ocean beneath Sputnik Planitia", "confidence": "inferred", "source": "Nimmo et al. 2016, Nature (New Horizons reorientation)" }, { "phase": "ice", "where": "water-ice \"bedrock\" under N₂/CH₄/CO surface ices", "confidence": "confirmed", "source": "Stern et al. 2015, Science (New Horizons)" } ], "CHARON": [ { "phase": "ice", "where": "water-ice surface (ammonia hydrates); an ANCIENT ocean, now frozen (Serenity Chasma tectonics)", "confidence": "inferred", "source": "Desch & Neveu 2017, Icarus (New Horizons)" } ], "JUPITER": [ { "phase": "vapour", "where": "deep tropospheric water; cloud base ~5 bar", "amount": "~2.7× protosolar O/H (equatorial)", "confidence": "inferred", "source": "Li et al. 2020, Nat. Astron. (Juno MWR)" } ], "SATURN": [ { "phase": "vapour", "where": "deep tropospheric water below ~10–20 bar (weakly constrained)", "amount": "~2–6× solar O (inferred)", "confidence": "inferred", "source": "Visscher & Fegley 2005, ApJ; Cassini disequilibrium tracers" } ], "URANUS": [ { "phase": "supercritical", "where": "bulk ionic / superionic water \"ice\" mantle under the H₂/He envelope", "amount": "~60–65% water by mass (~9–13 M⊕)", "confidence": "modelled", "source": "Helled et al. 2020, SSR; Millot et al. 2019, Nature (superionic ice)" } ], "NEPTUNE": [ { "phase": "supercritical", "where": "bulk ionic / superionic water \"ice\" mantle (drives the offset field)", "amount": "~60–65% water by mass", "confidence": "modelled", "source": "Helled et al. 2020, SSR; Militzer 2024, PNAS" } ] } }