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Evidence and data sources

Where the numbers come from

Every object in Space Time carries aspect-scoped provenance: its position, orbit, physical data and appearance each name an origin and a source. These pages publish those records so you can check them without opening the app. A reconstruction is labelled a reconstruction, a picture is labelled a picture, and an undocumented value says so.

ObservedCatalogComputedReconstructedIllustrativeUndocumented

Open Space Time

Dataset freshness

Source dates come from verified Blob publications or reviewed reference manifests. Retrieval and successful-check times are distinct from observation epochs. The table identifies scheduled refreshes, build-generated assets and manual releases. For every scheduled publication, open Data freshness.

Datasets, their source dates, horizons and refresh cadence.
DatasetBundle updatedHorizonAutomated
Current comets and near-Earth asteroids
Source retrieved:
Osculating elements at the snapshot epoch; propagated as two-body conics Yes, daily (Trigger.dev)
Trigger.dev → private Blob snapshots
Last successful check: 23 October 2026 · success
Searchable comet catalog (all comets)
Source retrieved:
Every JPL comet record with elements and photometric parameters Yes, daily (Trigger.dev)
Trigger.dev → private Blob snapshots
Last successful check: 23 October 2026 · success
Bright numbered asteroids (H < 13)
Source retrieved:
Elements at each body's own epoch; no covariance Yes, daily (Trigger.dev)
Trigger.dev → private Blob snapshots
Last successful check: 23 October 2026 · success
Exoplanet systems (pscomppars)
Source retrieved:
Confirmed planets only; composite parameters as published at the snapshot Yes, weekly (Trigger.dev)
Trigger.dev → private Blob snapshots
Last successful check: 5 October 2026 · success
Recent catalog additions
Derived from the JPL and Exoplanet Archive snapshots
Source retrieved:
Difference between the two most recent refreshes Yes, daily (Trigger.dev)
Derived atomically with each source catalog snapshot
Last successful check: 5 October 2026 · success
NGC/IC deep-sky catalog
OpenNGC · CC-BY-SA-4.0
ICRS/J2000 positions, magnitudes and sizes as supplied No, refreshed by hand
scripts/build-ngc-catalog
Nearest Gaia DR3 sources Epoch 2016.0 astrometry with proper motion and covariance for parallax > 40 mas No, refreshed by hand
scripts/build-gaia-nearby
Planetary satellite mean elements Mean elements (a, e, i, period) for every known natural satellite No, refreshed by hand
npm run generate:moons
Double and variable stars WDS pairs with primary mag <= 8; GCVS variables with max mag <= 10 No, refreshed by hand
npm run generate:star-extras
Extended deep-sky catalogs Positions, sizes and magnitudes as catalogued No, refreshed by hand
npm run generate:extended-dso
Quasars and AGN V <= 17 objects with redshift and class No, refreshed by hand
npm run generate:quasars
Messier, Caldwell and Herschel 400 lists
Cross-referenced to the local NGC/IC catalog
Program membership and positions No, refreshed by hand
npm run generate:programs
Sky events calendar (.ics) Next 24 months from the generation date Yes, weekly (Monday data job)
npm run generate:calendar
Spacecraft trajectories (Blob snapshots)
Source retrieved:
Per craft: each evidence page states the first and last sample date Yes, daily (Trigger.dev)
Trigger.dev → private Blob snapshots; preserved historical encounter samples
Last successful check: 23 October 2026 · success
Satellite orbital elements (CelesTrak GP)
Source retrieved:
Published UTC element epochs; SGP4 propagation with dated current/previous Blob snapshots Every two hours (Trigger.dev)
Trigger.dev → private Blob snapshots
Last successful check: 13 October 2026 · fetch failure
Sun, Moon and planet positions no snapshot date Valid roughly 1700 to 2200 at arcminute level; no snapshot to age Not applicable (analytic model)
npm dependency

Sun and planets (9)

Dwarf planets (9)

Moons (48)

Spacecraft and missions (43)

Comets, asteroids and interstellar visitors (32)

Earth satellites (3)

Stars, star systems, pulsars and black holes (48)

Exoplanet systems (6)

Galaxies with observation-based destinations (14)

Nebulae with evidence models (45)

Supernova remnants (5)

Sky events and alerts (1)

How to read a page

  • Observed: a direct measurement or image from an instrument.
  • Catalog: a value copied from a published catalog or paper, with the retrieval date where a snapshot exists.
  • Computed: calculated by a documented model (astronomy-engine, a Kepler solver, SGP4) from published inputs.
  • Reconstructed: a 3D interpretation built from measurements. The measurements are real; the volume between them is not observed.
  • Illustrative: a picture or schematic chosen so you can see the object at all. Not a measurement.
  • Undocumented: the catalog file does not record where the value came from. The value may well be right; the page does not claim it is.

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