{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"e4e34f28f5345ee154dd8905f63164ff9be89c29db8ba36230e8a806c548a49e","created":"2026-10-03T07:18:03Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"a2eb9acd174cbb94dba881be8b126e9689b4ab9f8694a5d80e7e8f97fa04eafa","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"earth.planetary-dynamos.mercury-weak-field","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"plain":"Mercury has an active dynamo (a field generator made by flowing liquid iron) but its field is about a hundred times weaker than simple scaling predicts, and its center is shifted toward the north pole. Its large iron core should do better.","posed_since":"1974","precise":"MESSENGER found an axial dipole field with surface equatorial strength near 2e-3 G whose magnetic equator is offset about 0.2 Mercury radii north. Identify the core state (dynamo beneath a stably stratified layer, iron-snow regime, thin-shell convection) that reproduces both the weakness and the offset. An answer is a dynamo model fitting the measured low-degree Gauss coefficients and their secular variation.","problem_ref":null,"references":"","settled_by":"BepiColombo two-spacecraft field measurements of higher harmonics and secular variation compared with dynamo models.","status_note":"BepiColombo was scheduled to enter Mercury orbit in late 2026; data are not yet available.","title":"Why is Mercury's magnetic field so weak and shifted north?","topic_ref":"d630b91b3d151b4fd563599f0c63c42ed19209d89bcb67e4ebbd2cdaddd50144"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"afae90e22d64c05ef5160b1b30645756f5faed87e54e1e8d8751c8634f6d09ee","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"1150ed87ac48589c0bdb7e11cbdb3280370c56e8a05c9b2e8326f673f869c345","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"9ytp3FDT0bGhziVfo_iiakV30wmontTUO36hKulUSEI2oaY1DWKUJ6N6wHMha3C8S35TN_nQrN6RdM8TvaCvAg"},"schema":"pubphys.envelope/1"},"record_hash":"afae90e22d64c05ef5160b1b30645756f5faed87e54e1e8d8751c8634f6d09ee","leaf_index":1357}