{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"efa90c411a48b12e20ca557a07b520967215c186edded546686a6bf8439dfb7d","created":"2026-10-03T07:18:03Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"57b23868d9d62684f6b6b3c1ec07a2da51388bc2c68daac73b810cdae8015f44","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"earth.giant-planet-interiors.helium-rain","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"At high pressure, helium may stop mixing with hydrogen and sink as droplets, releasing heat. This could explain why Saturn is warmer than expected and why both atmospheres lack helium.","posed_since":"","precise":"Determine the pressure-temperature extent of hydrogen-helium immiscibility in Jupiter and Saturn and the amount of helium depleted from the outer envelopes (the Galileo probe measured helium mass fraction about 0.234 versus a protosolar value near 0.27). An answer is an immiscibility curve and evolutionary model that fits both planets' atmospheric helium, luminosity and gravity.","problem_ref":null,"references":"","settled_by":"Ab initio and shock-compression determination of the H-He miscibility gap combined with evolution models fitting both planets.","status_note":"","title":"Where and how much does helium rain out inside Jupiter and Saturn?","topic_ref":"98930448b979604a081578cbdcee93172ed4efa6774dcfbd338efa6dd2e302c0"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"ff0afe5360cb947c1721ddb4b372c81f06d8bdbe1e8ab9083f1336535364fc4d","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"cd9061bb701ce7b412a8f657a578569b61d47d56c86a14be943d5298b9269e5c","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"cGekSOw3oGy26a2FxbVU5Juz7KzZu1MwLK-O2t_8aqnRCnKafnwci0fdnkkmGCMJIDAR8u4qLNWE3HDuiZaUBQ"},"schema":"pubphys.envelope/1"},"record_hash":"ff0afe5360cb947c1721ddb4b372c81f06d8bdbe1e8ab9083f1336535364fc4d","leaf_index":1323}