{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2015:SEJFAM2HUU5B2F3SJIVGQMULLL","short_pith_number":"pith:SEJFAM2H","canonical_record":{"source":{"id":"1509.03210","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2015-09-10T16:09:21Z","cross_cats_sorted":[],"title_canon_sha256":"f3b29f72754847da0d9bf3955cfb7209a1346d210c7d039b393bd75761b8a237","abstract_canon_sha256":"43a6120cc8b186daea676100ae9c6211ba7329cf9b6e0b4abee0c277a1c2222e"},"schema_version":"1.0"},"canonical_sha256":"9112503347a53a1d17724a2a68328b5aca2c0dda515cbbac464895c5dcf775f8","source":{"kind":"arxiv","id":"1509.03210","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1509.03210","created_at":"2026-05-18T01:33:25Z"},{"alias_kind":"arxiv_version","alias_value":"1509.03210v1","created_at":"2026-05-18T01:33:25Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1509.03210","created_at":"2026-05-18T01:33:25Z"},{"alias_kind":"pith_short_12","alias_value":"SEJFAM2HUU5B","created_at":"2026-05-18T12:29:39Z"},{"alias_kind":"pith_short_16","alias_value":"SEJFAM2HUU5B2F3S","created_at":"2026-05-18T12:29:39Z"},{"alias_kind":"pith_short_8","alias_value":"SEJFAM2H","created_at":"2026-05-18T12:29:39Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2015:SEJFAM2HUU5B2F3SJIVGQMULLL","target":"record","payload":{"canonical_record":{"source":{"id":"1509.03210","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2015-09-10T16:09:21Z","cross_cats_sorted":[],"title_canon_sha256":"f3b29f72754847da0d9bf3955cfb7209a1346d210c7d039b393bd75761b8a237","abstract_canon_sha256":"43a6120cc8b186daea676100ae9c6211ba7329cf9b6e0b4abee0c277a1c2222e"},"schema_version":"1.0"},"canonical_sha256":"9112503347a53a1d17724a2a68328b5aca2c0dda515cbbac464895c5dcf775f8","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:33:25.052808Z","signature_b64":"Rf4SAYg40P/2zhlLRg/lVrcaxbPlCKOY132orGfASAYYAhhWnEYdnpd9TQ/AfVXM+CeFGadwRGajrBBtO5JoBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"9112503347a53a1d17724a2a68328b5aca2c0dda515cbbac464895c5dcf775f8","last_reissued_at":"2026-05-18T01:33:25.052365Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:33:25.052365Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1509.03210","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:33:25Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"5TTULNIIW+OEgKKnhSesm5FloZj0ZJaA7VnUpm62XwfKFDjJgIP3Thwv0zMb30/ZVdW9felP2eWOubkTmzJTAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-30T17:58:45.992295Z"},"content_sha256":"3e507c692071863ed728e280253eff68ef608e30c6ba3f040de8fabbcb322bf5","schema_version":"1.0","event_id":"sha256:3e507c692071863ed728e280253eff68ef608e30c6ba3f040de8fabbcb322bf5"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2015:SEJFAM2HUU5B2F3SJIVGQMULLL","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Widespread Excess Ice in Arcadia Planitia, Mars","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.EP","authors_text":"Ali M. Bramson, Jeffrey J. Plaut, John W. Holt, Nathaniel E. Putzig, Sarah Sutton, Shane Byrne, T. Charles Brothers","submitted_at":"2015-09-10T16:09:21Z","abstract_excerpt":"The distribution of subsurface water ice on Mars is a key constraint on past climate, while the volumetric concentration of buried ice (pore-filling versus excess) provides information about the process that led to its deposition. We investigate the subsurface of Arcadia Planitia by measuring the depth of terraces in simple impact craters and mapping a widespread subsurface reflection in radar sounding data. Assuming that the contrast in material strengths responsible for the terracing is the same dielectric interface that causes the radar reflection, we can combine these data to estimate the "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1509.03210","kind":"arxiv","version":1},"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":"2026-05-18T01:33:25Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"CGejI0ZtLNgLwmiplrcxd7/vyiGp7qJr7cI/m3rHtSKTFvEgXJDSGzYljSJGMoSfFPu2uH6DoZJoEjgpFFSSCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-30T17:58:45.992643Z"},"content_sha256":"ea5133412d16fef98da45d0669930feb6eedcc1404e88304620fa3b91bf1c070","schema_version":"1.0","event_id":"sha256:ea5133412d16fef98da45d0669930feb6eedcc1404e88304620fa3b91bf1c070"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/SEJFAM2HUU5B2F3SJIVGQMULLL/bundle.json","state_url":"https://pith.science/pith/SEJFAM2HUU5B2F3SJIVGQMULLL/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/SEJFAM2HUU5B2F3SJIVGQMULLL/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":"2026-06-30T17:58:45Z","links":{"resolver":"https://pith.science/pith/SEJFAM2HUU5B2F3SJIVGQMULLL","bundle":"https://pith.science/pith/SEJFAM2HUU5B2F3SJIVGQMULLL/bundle.json","state":"https://pith.science/pith/SEJFAM2HUU5B2F3SJIVGQMULLL/state.json","well_known_bundle":"https://pith.science/.well-known/pith/SEJFAM2HUU5B2F3SJIVGQMULLL/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2015:SEJFAM2HUU5B2F3SJIVGQMULLL","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":"43a6120cc8b186daea676100ae9c6211ba7329cf9b6e0b4abee0c277a1c2222e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2015-09-10T16:09:21Z","title_canon_sha256":"f3b29f72754847da0d9bf3955cfb7209a1346d210c7d039b393bd75761b8a237"},"schema_version":"1.0","source":{"id":"1509.03210","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1509.03210","created_at":"2026-05-18T01:33:25Z"},{"alias_kind":"arxiv_version","alias_value":"1509.03210v1","created_at":"2026-05-18T01:33:25Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1509.03210","created_at":"2026-05-18T01:33:25Z"},{"alias_kind":"pith_short_12","alias_value":"SEJFAM2HUU5B","created_at":"2026-05-18T12:29:39Z"},{"alias_kind":"pith_short_16","alias_value":"SEJFAM2HUU5B2F3S","created_at":"2026-05-18T12:29:39Z"},{"alias_kind":"pith_short_8","alias_value":"SEJFAM2H","created_at":"2026-05-18T12:29:39Z"}],"graph_snapshots":[{"event_id":"sha256:ea5133412d16fef98da45d0669930feb6eedcc1404e88304620fa3b91bf1c070","target":"graph","created_at":"2026-05-18T01:33:25Z","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":"The distribution of subsurface water ice on Mars is a key constraint on past climate, while the volumetric concentration of buried ice (pore-filling versus excess) provides information about the process that led to its deposition. We investigate the subsurface of Arcadia Planitia by measuring the depth of terraces in simple impact craters and mapping a widespread subsurface reflection in radar sounding data. Assuming that the contrast in material strengths responsible for the terracing is the same dielectric interface that causes the radar reflection, we can combine these data to estimate the ","authors_text":"Ali M. Bramson, Jeffrey J. Plaut, John W. Holt, Nathaniel E. Putzig, Sarah Sutton, Shane Byrne, T. Charles Brothers","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2015-09-10T16:09:21Z","title":"Widespread Excess Ice in Arcadia Planitia, Mars"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1509.03210","kind":"arxiv","version":1},"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":"sha256:3e507c692071863ed728e280253eff68ef608e30c6ba3f040de8fabbcb322bf5","target":"record","created_at":"2026-05-18T01:33:25Z","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":"43a6120cc8b186daea676100ae9c6211ba7329cf9b6e0b4abee0c277a1c2222e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.EP","submitted_at":"2015-09-10T16:09:21Z","title_canon_sha256":"f3b29f72754847da0d9bf3955cfb7209a1346d210c7d039b393bd75761b8a237"},"schema_version":"1.0","source":{"id":"1509.03210","kind":"arxiv","version":1}},"canonical_sha256":"9112503347a53a1d17724a2a68328b5aca2c0dda515cbbac464895c5dcf775f8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"9112503347a53a1d17724a2a68328b5aca2c0dda515cbbac464895c5dcf775f8","first_computed_at":"2026-05-18T01:33:25.052365Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:33:25.052365Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Rf4SAYg40P/2zhlLRg/lVrcaxbPlCKOY132orGfASAYYAhhWnEYdnpd9TQ/AfVXM+CeFGadwRGajrBBtO5JoBw==","signature_status":"signed_v1","signed_at":"2026-05-18T01:33:25.052808Z","signed_message":"canonical_sha256_bytes"},"source_id":"1509.03210","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:3e507c692071863ed728e280253eff68ef608e30c6ba3f040de8fabbcb322bf5","sha256:ea5133412d16fef98da45d0669930feb6eedcc1404e88304620fa3b91bf1c070"],"state_sha256":"bcebd9463bf34deb9c6977b1a0e72d0f4b6104aa25c8b06ec48329921a4ded65"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"/y5WUSnOeaNmEeIg3sA0wPZ1Lvp2xNmboRaEkMkIO78NTNey0Y1P/S7ZjkLqv3XP2UO0PPfnzcvdvWYxsCoGAg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-30T17:58:45.994766Z","bundle_sha256":"66d38d4e415ef86c61c77868a3ab109f260e851e453aa1e33af81259ffb94038"}}