{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"dcca070542c631ad620db738fc4e9d76c6855836f192325c41b1b4848be7d23a","created":"2026-10-03T07:17:54Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","da92d3f1d7a60499e542e73e436006381ac73aca274660db5084ef7e440fe2d5"],"salt":"7d089e3e1d3f28569366374f43db7040c66eb6ef7ce421f1abf18ce00c7ca563","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"astro.biosignatures.cosmic-shoreline","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"","parent_revision":"da92d3f1d7a60499e542e73e436006381ac73aca274660db5084ef7e440fe2d5","relation":"special_case"}],"plain":"In the Solar System, bodies that are small or strongly heated have no air, and the dividing line follows a simple rule linking gravity and sunlight. Whether exoplanets follow the same line is untested.","posed_since":"2017","precise":"Test whether atmosphere retention among rocky exoplanets follows the cosmic shoreline relation $I \\text{ proportional to } v_{\\mathrm{esc}}^4$ (I the cumulative XUV or bolometric instellation, v_esc the escape speed) proposed from Solar System bodies, and measure its location and width for M-dwarf and FGK hosts. The answer is the boundary in the $(v_{\\mathrm{esc}}, I)$ plane with its scatter.","problem_ref":null,"references":"","settled_by":"Atmosphere detections and non-detections for a sample of rocky planets spanning at least an order of magnitude in $v_{\\mathrm{esc}}$ and instellation.","status_note":"","title":"Is there a sharp boundary between airless and atmosphere-bearing planets?","topic_ref":"59b283291ab553a122fd70aabfbd2c1ce03ef623f8bb56636d5ec28be91c14ab"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"0d1541ba7d7489c9807bf72ce3bdd8b8a2383bbc147f3d123f0c9a345b3d375d","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"688a845f3b6ae5ec065cb89421189b1fc14868721a32110644a82e632837973d","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"gVlq3pgyED5PKijkhkESvvVC8LLV8YBLdOpjjanz1xBJ6SInC8nszEzU7Uo37LBGNFwmhkFk5HidTkrtHz6yDQ"},"schema":"pubphys.envelope/1"},"record_hash":"0d1541ba7d7489c9807bf72ce3bdd8b8a2383bbc147f3d123f0c9a345b3d375d","leaf_index":489}