{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2009:E4I2ZGRE77ZBPOOPTKTOEDTW7P","short_pith_number":"pith:E4I2ZGRE","canonical_record":{"source":{"id":"0911.5621","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2009-11-30T20:33:21Z","cross_cats_sorted":[],"title_canon_sha256":"98865c5b028150986ea4aa95a91e2459a2cae42303c9e28b2af8a4a14a976837","abstract_canon_sha256":"80cd1e2c1e8f4d75eb51a92d41b07fece2e3fc935780dc19700733d5a0dfeeeb"},"schema_version":"1.0"},"canonical_sha256":"2711ac9a24fff217b9cf9aa6e20e76fbfd7f7c7ff850e14a4c0008e1f6c9f647","source":{"kind":"arxiv","id":"0911.5621","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0911.5621","created_at":"2026-05-18T02:34:03Z"},{"alias_kind":"arxiv_version","alias_value":"0911.5621v2","created_at":"2026-05-18T02:34:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0911.5621","created_at":"2026-05-18T02:34:03Z"},{"alias_kind":"pith_short_12","alias_value":"E4I2ZGRE77ZB","created_at":"2026-05-18T12:25:59Z"},{"alias_kind":"pith_short_16","alias_value":"E4I2ZGRE77ZBPOOP","created_at":"2026-05-18T12:25:59Z"},{"alias_kind":"pith_short_8","alias_value":"E4I2ZGRE","created_at":"2026-05-18T12:25:59Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2009:E4I2ZGRE77ZBPOOPTKTOEDTW7P","target":"record","payload":{"canonical_record":{"source":{"id":"0911.5621","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2009-11-30T20:33:21Z","cross_cats_sorted":[],"title_canon_sha256":"98865c5b028150986ea4aa95a91e2459a2cae42303c9e28b2af8a4a14a976837","abstract_canon_sha256":"80cd1e2c1e8f4d75eb51a92d41b07fece2e3fc935780dc19700733d5a0dfeeeb"},"schema_version":"1.0"},"canonical_sha256":"2711ac9a24fff217b9cf9aa6e20e76fbfd7f7c7ff850e14a4c0008e1f6c9f647","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:34:03.039571Z","signature_b64":"VRj2EEbFDh0n/e93oQpnNXgVS7/zVoEOKY5UgvCqX75knRB7Speps92Rk1sd/oM7n9aGhpdpoRNNtSHRK1VKDA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"2711ac9a24fff217b9cf9aa6e20e76fbfd7f7c7ff850e14a4c0008e1f6c9f647","last_reissued_at":"2026-05-18T02:34:03.038990Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:34:03.038990Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0911.5621","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T02:34:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"u4owsxVEJrqWqroLMnRDZKl5IFFSHDwZlGM3rUNlguTz5c/FWy33toircSCo7JVWsn+4JABNEqn997ZsyZYPCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T16:39:34.635216Z"},"content_sha256":"1cc791c4705b4fddef33980b2194f441315b836e3a2dc5f8ca54d2c157cf01bb","schema_version":"1.0","event_id":"sha256:1cc791c4705b4fddef33980b2194f441315b836e3a2dc5f8ca54d2c157cf01bb"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2009:E4I2ZGRE77ZBPOOPTKTOEDTW7P","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Colors of a Second Earth: Estimating the fractional areas of ocean, land, and vegetation of Earth-like exoplanets","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.EP","authors_text":"A. Taruya, E. L. Turner, H. Kawahara, S. Fukuda, T. Nakajima, Y. Fujii (U. of Tokyo), Y. Suto","submitted_at":"2009-11-30T20:33:21Z","abstract_excerpt":"Characterizing the surfaces of rocky exoplanets via the scattered light will be an essential challenge to investigate the existence of life on habitable exoplanets. We present a simple reconstruction method for fractional areas of different surface types from photometric variations, or colors, of a second Earth. We create mock light curves for Earth without clouds using empirical data. Then these light curves are fitted to the isotropic scattering model consisting of 4 surface types: ocean, soil, snow and vegetation. In an idealized situation where the photometric errors are only photon shot n"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0911.5621","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T02:34:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ndkIfVSo6a3C9XvYPTGCdMFgnBYd1I9GqdxCm7sjXK5Zdf8juJiIiOmCaFJxvTEdBE8t7RrQoemj9LFKvNcwBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-25T16:39:34.635888Z"},"content_sha256":"16d05e75c85c2d9e638ac547d80583937bc58f101cf9398e2a88638493d2aeb3","schema_version":"1.0","event_id":"sha256:16d05e75c85c2d9e638ac547d80583937bc58f101cf9398e2a88638493d2aeb3"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/E4I2ZGRE77ZBPOOPTKTOEDTW7P/bundle.json","state_url":"https://pith.science/pith/E4I2ZGRE77ZBPOOPTKTOEDTW7P/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/E4I2ZGRE77ZBPOOPTKTOEDTW7P/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-25T16:39:34Z","links":{"resolver":"https://pith.science/pith/E4I2ZGRE77ZBPOOPTKTOEDTW7P","bundle":"https://pith.science/pith/E4I2ZGRE77ZBPOOPTKTOEDTW7P/bundle.json","state":"https://pith.science/pith/E4I2ZGRE77ZBPOOPTKTOEDTW7P/state.json","well_known_bundle":"https://pith.science/.well-known/pith/E4I2ZGRE77ZBPOOPTKTOEDTW7P/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:E4I2ZGRE77ZBPOOPTKTOEDTW7P","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"80cd1e2c1e8f4d75eb51a92d41b07fece2e3fc935780dc19700733d5a0dfeeeb","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2009-11-30T20:33:21Z","title_canon_sha256":"98865c5b028150986ea4aa95a91e2459a2cae42303c9e28b2af8a4a14a976837"},"schema_version":"1.0","source":{"id":"0911.5621","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0911.5621","created_at":"2026-05-18T02:34:03Z"},{"alias_kind":"arxiv_version","alias_value":"0911.5621v2","created_at":"2026-05-18T02:34:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0911.5621","created_at":"2026-05-18T02:34:03Z"},{"alias_kind":"pith_short_12","alias_value":"E4I2ZGRE77ZB","created_at":"2026-05-18T12:25:59Z"},{"alias_kind":"pith_short_16","alias_value":"E4I2ZGRE77ZBPOOP","created_at":"2026-05-18T12:25:59Z"},{"alias_kind":"pith_short_8","alias_value":"E4I2ZGRE","created_at":"2026-05-18T12:25:59Z"}],"graph_snapshots":[{"event_id":"sha256:16d05e75c85c2d9e638ac547d80583937bc58f101cf9398e2a88638493d2aeb3","target":"graph","created_at":"2026-05-18T02:34:03Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"Characterizing the surfaces of rocky exoplanets via the scattered light will be an essential challenge to investigate the existence of life on habitable exoplanets. We present a simple reconstruction method for fractional areas of different surface types from photometric variations, or colors, of a second Earth. We create mock light curves for Earth without clouds using empirical data. Then these light curves are fitted to the isotropic scattering model consisting of 4 surface types: ocean, soil, snow and vegetation. In an idealized situation where the photometric errors are only photon shot n","authors_text":"A. Taruya, E. L. Turner, H. Kawahara, S. Fukuda, T. Nakajima, Y. Fujii (U. of Tokyo), Y. Suto","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2009-11-30T20:33:21Z","title":"Colors of a Second Earth: Estimating the fractional areas of ocean, land, and vegetation of Earth-like exoplanets"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0911.5621","kind":"arxiv","version":2},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:1cc791c4705b4fddef33980b2194f441315b836e3a2dc5f8ca54d2c157cf01bb","target":"record","created_at":"2026-05-18T02:34:03Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"80cd1e2c1e8f4d75eb51a92d41b07fece2e3fc935780dc19700733d5a0dfeeeb","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2009-11-30T20:33:21Z","title_canon_sha256":"98865c5b028150986ea4aa95a91e2459a2cae42303c9e28b2af8a4a14a976837"},"schema_version":"1.0","source":{"id":"0911.5621","kind":"arxiv","version":2}},"canonical_sha256":"2711ac9a24fff217b9cf9aa6e20e76fbfd7f7c7ff850e14a4c0008e1f6c9f647","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"2711ac9a24fff217b9cf9aa6e20e76fbfd7f7c7ff850e14a4c0008e1f6c9f647","first_computed_at":"2026-05-18T02:34:03.038990Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:34:03.038990Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"VRj2EEbFDh0n/e93oQpnNXgVS7/zVoEOKY5UgvCqX75knRB7Speps92Rk1sd/oM7n9aGhpdpoRNNtSHRK1VKDA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:34:03.039571Z","signed_message":"canonical_sha256_bytes"},"source_id":"0911.5621","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:1cc791c4705b4fddef33980b2194f441315b836e3a2dc5f8ca54d2c157cf01bb","sha256:16d05e75c85c2d9e638ac547d80583937bc58f101cf9398e2a88638493d2aeb3"],"state_sha256":"204692032576aef2ad9d5d63ddf9cbc2483042de3d5e6f982b3e2f9e2a285b73"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rnNecbrHhqix8qs6keSksgbrgKqdrc1onHRP/Vbd3T3vP6t9glMyfUReIp/WsX3uOPPgySk9BkN412fermNLBw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-25T16:39:34.639752Z","bundle_sha256":"2d8d90f130e1b7225e29bdf0cc4d66f560803afd653786b0bee1a938407c42ca"}}