{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"7f148d1eb3b10e692583f096a4c31fead18740b9be1215049e8d1e19e1b9015b","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5e67d4f52e45b20350abba975abfc3ba829196f2e1b2485f2ba5959692bfdb06","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"7fdcf52aecac04ab33e5f8fdd0e37a907377f075b4812593c6a6c47888659384","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"classification","assisted_by":[],"external_id":"astro.interstellar-objects.composition","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"2I/Borisov carried an unusually large share of carbon monoxide and 3I/ATLAS showed a coma dominated by carbon dioxide. Whether such differences reflect where they formed or billions of years of cosmic-ray exposure in space is unknown.","posed_since":"","precise":"Compare volatile and metal abundance ratios ($\\mathrm{CO}/\\mathrm{H2O}, \\mathrm{CO2}/\\mathrm{H2O}, \\mathrm{Ni}/\\mathrm{Fe}$) of 2I/Borisov and 3I/ATLAS with Solar System comets, and determine whether the differences reflect formation location and stellar environment or processing during Gyr-long interstellar travel. The answer is a classification of composition differences by origin, with predictions testable on future objects.","problem_ref":"5e67d4f52e45b20350abba975abfc3ba829196f2e1b2485f2ba5959692bfdb06","references":"","settled_by":"Spectroscopic surveys of a sample of interstellar comets compared with laboratory and model predictions of cosmic-ray processing of ices.","status_note":"JWST spectra in 2025 showed a $\\mathrm{CO_2}$-dominated coma of 3I/ATLAS ($\\mathrm{CO2}/\\mathrm{H2O} \\sim 8$), VLT spectra detected nickel vapor with little or no iron, and its non-gravitational acceleration near perihelion is attributed to outgassing.","title":"Do interstellar comets differ in composition from Solar System comets?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"bc191e202f25779f56e14bc2c68f2cac77be57fb586b432cb078fe8c19238070","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"95d0d935ddade6859c6e9403d45296e70303d5c7a0b3f011a12e6479ae001824","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"1QBExqtAllQU7B6f25yo4SBpkx7Mr0wnIex2ggmCoXaZ6AbH-_FaWWhaAqeRsUJSkymMxycSutjRHDxUKFKoAw"},"schema":"pubphys.envelope/1"},"record_hash":"bc191e202f25779f56e14bc2c68f2cac77be57fb586b432cb078fe8c19238070","leaf_index":2380}