Publisher source
The Minor Planet Center (MPC) is the international clearinghouse for small-body astrometry and object designations. The Small Bodies Node (SBN) provides database replication services for the MPC database, and the Asteroid Institute maintains a BigQuery MPC Database Replica available through Google Cloud Analytics Hub.
The replica separates published observations, provisional NEOCP workflow records, and object-identity relationships. Those sources have different scientific meanings and are not interchangeable.
MPC source tables used by AIMS and Precovery
| MPC replica table | Source semantics and use |
|---|---|
public_obs_sbn | Published MPC observations. This is the source normalized into AIMS mpc observation rows and used as the published-observation reference. |
public_neocp_obs | Observations currently associated with active Near-Earth Object Confirmation Page candidates. |
public_neocp_obs_archive | Archived NEOCP observations for candidates no longer represented by the active table. |
public_neocp_prev_des | Previous-designation relationships used to follow NEOCP candidate designation changes. |
public_primary_objects | Primary MPC object records used as stable anchors for current identity resolution. |
public_current_identifications | Current relationships between primary and secondary provisional designations. |
public_numbered_identifications | Permanent-number relationships to primary provisional designations. |
public_obscodes | Observatory-code metadata for MPC stations; normalized observation rows retain the station code itself. |
public_mpc_orbits and related views | Orbit context in the replica. AIMS observation normalization and attribution do not use orbit propagation to decide whether two rows match. |
The active and archived NEOCP tables describe a provisional confirmation workflow. Presence there does not mean an observation has been published in public_obs_sbn or assigned a final MPC identity.
What AIMS selects and normalizes
AIMS selects public_obs_sbn rows with usable observation time, station code, RA, Dec, and source HEALPix. It preserves the MPC observation id as both the normalized observation and point-exposure identity.
| AIMS field | MPC source or derivation |
|---|---|
observation_id, exposure_id | public_obs_sbn.id converted to string. |
dataset_id | Constant mpc. |
observatory_code | MPC station code stn. |
| Observation and midpoint time | obstime represented as UTC MJD and timestamp; the point observation time is also the AIMS exposure midpoint. |
exposure_duration_s | exp when present and parseable. |
ra_deg, dec_deg | Published MPC RA and Dec in degrees. |
ra_sigma_deg, dec_sigma_deg | rmsra, rmsdec converted from arcseconds to degrees when present. |
mag, mag_sigma | mag, rmsmag when present. |
filter | Published MPC band value. |
healpixel | Source nside=32768 NESTED HEALPix downsampled to AIMS nside=128 NESTED. |
Object designations and publication status remain identity context rather than being embedded as immutable claims in the common AIMS detection row.
Identity and attribution products
AIMS publishes several distinct products in its BigQuery dataset so consumers can separate measurements from interpretation:
aims_mpc_hotandaims_mpc_archivecontain normalized MPC observation rows;aims_detections_unifiedexposes those rows with the normalized survey detections;mpc_designation_lookup_v1resolves published designation forms to the current canonical MPC object anchor;mpc_obs_identity_v1records the current identity associated with each published MPC observation;observation_attribution_edges_v2records observation-level matches between native AIMS detections and published MPC observations.
Attribution uses observatory, time, and sky position to determine whether two records plausibly represent the same observation. It is kept separate from the source rows because geometric equivalence and current object identity can change on different schedules.
Parquet products
Normalized MPC rows are exported to Google Cloud Storage in aims_detections_parquet for daily hot partitions and aims_detections_parquet_archive for older monthly partitions, identified by dataset_id = mpc. AIMS derives corresponding point-exposure frame indexes in aims_frames_parquet and aims_frames_parquet_archive. Complete detection/frame pairs are listed in aims_unified_parquet_catalog/catalog.json for consumers such as Precovery.
The Parquet representation changes storage and indexing, not the published MPC measurement values. The same physical measurement may have both an MPC row and a native-survey row; the attribution product carries that relationship rather than deleting either provenance.
NEOCP and JPL Scout downstream context
The Near-Earth Object Confirmation Page (NEOCP) is an MPC workflow for recent candidates requiring confirmation. Active, archived, and previous-designation tables let Precovery interpret that evolving workflow without treating provisional rows as published MPC observations.
JPL Scout is a downstream orbit and hazard-assessment service, not a source table in the MPC replica. When a Precovery search uses a Scout orbit, Scout’s fitted-observation response defines the observations used by that orbit solution. Matching NEOCP replica rows can provide MPC workflow context, but neither Scout membership nor an NEOCP record promotes an observation into the canonical AIMS catalog or proves publication in public_obs_sbn.
Scientific validity and limitations
- AIMS preserves published MPC astrometry and photometry apart from documented type, unit, time, and HEALPix conversions. It does not re-reduce or recalibrate MPC measurements.
- MPC RMS fields are optional. Missing values remain null, and the common AIMS row does not preserve MPC cross-axis correlation or a full covariance.
- Published observations and native survey rows can be two representations of one physical measurement. They should not be treated as independent evidence without consulting attribution.
- Observation attribution is a spatial-temporal provenance match, not orbit linking, object classification, or proof of a globally unique counterpart.
- Designations, status, and object associations can change as the MPC corrects or links records. Current labels should be read from the identity products rather than assumed immutable from the source observation row.
- NEOCP active/archive state is provisional and mutable. A Scout fitted-observation set is tied to a particular Scout solution and can differ from later MPC publication or identity state.