Space Time
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
Dataset freshness
Snapshot dates are read from the generated manifests at request time. "Automated" says which refreshes run on their own and which need a person.
| Dataset | Last refreshed | Horizon | Automated |
|---|---|---|---|
| Current comets and near-Earth asteroids | no snapshot date | Osculating elements at the snapshot epoch; propagated as two-body conics | Yes, weekly (Monday data job) npm run fetch:data |
| Searchable comet catalog (all comets) | no snapshot date | Every JPL comet record with elements and photometric parameters | Yes, weekly (Monday data job) npm run generate:comets |
| Bright numbered asteroids (H < 13) | no snapshot date | Elements at each body's own epoch; no covariance | Yes, weekly (Monday data job) npm run generate:asteroids |
| Exoplanet systems (pscomppars) | no snapshot date | Confirmed planets only; composite parameters as published at the snapshot | Yes, weekly (Monday data job) npm run generate:exoplanets |
| Recent catalog additions Derived from the JPL and Exoplanet Archive snapshots |
no snapshot date | Difference between the two most recent refreshes | Yes, weekly (Monday data job) npm run generate:catalog-changes |
| NGC/IC deep-sky catalog OpenNGC · CC-BY-SA-4.0 |
no snapshot date | ICRS/J2000 positions, magnitudes and sizes as supplied | No, refreshed by hand scripts/build-ngc-catalog |
| Nearest Gaia DR3 sources | no snapshot date | 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 | no snapshot date | Mean elements (a, e, i, period) for every known natural satellite | No, refreshed by hand npm run generate:moons |
| Double and variable stars | no snapshot date | 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 | no snapshot date | Positions, sizes and magnitudes as catalogued | No, refreshed by hand npm run generate:extended-dso |
| Quasars and AGN | no snapshot date | 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 |
no snapshot date | Program membership and positions | No, refreshed by hand npm run generate:programs |
| Sky events calendar (.ics) | no snapshot date | Next 24 months from the generation date | Yes, weekly (Monday data job) npm run generate:calendar |
| Spacecraft trajectories (baked keyframes) | no snapshot date | Per craft: each evidence page states the first and last sample date | No, refreshed by hand scripts/bake-trajectories.mjs |
| Bundled satellite element sets (ISS, Tiangong, Hubble) | Element epoch in the TLE; the app fetches live sets first and falls back to this bundle | Yes, every production build scripts/refresh-tle.mjs (prebuild) |
|
| 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)
AdrasteaAmaltheaArielAtlasCallistoCharonCordeliaDaphnisDeimosDespinaDimorphosDioneEnceladusEpimetheusEuropaGalateaGanymedeHydraHyperionIapetusIoJanusKerberosMetisMimasMirandaMoonNereidNixOberonOpheliaPanPandoraPhobosPhoebePortiaPrometheusProteusRheaRosalindSelamStyxTethysThebeTitanTitaniaTritonUmbriel
Spacecraft and missions (43)
BepiColomboBioSentinelCassiniChandra X-ray ObservatoryCuriosity RoverDARTDawnEuropa ClipperFermi Gamma-ray Space TelescopeGalileoHayabusa2Ingenuity HelicopterInSight LanderJames Webb Space TelescopeJUICEJunoKeplerLucyMagellanMars Global SurveyorMars OdysseyMars Reconnaissance OrbiterMAVENMESSENGERNEAR ShoemakerNew HorizonsOpportunity RoverOSIRIS-RExParker Solar ProbePerseverance RoverPhilaePioneer 10PsycheRosettaSolar OrbiterSpitzer Space TelescopeSTEREO-A (Ahead)TESSUlyssesViking 1 LanderViking 2 LanderVoyager 1Voyager 2
Comets, asteroids and interstellar visitors (32)
10 Hygiea101955 Bennu15 Eunomia16 Psyche162173 Ryugu1I/'Oumuamua1P/Halley2 Pallas21 Lutetia243 Ida25143 Itokawa253 Mathilde2867 Šteins2I/Borisov3 Juno3I/ATLAS4 Vesta4179 Toutatis433 Eros52246 Donaldjohanson65803 Didymos67P/Churyumov-Gerasimenko951 Gaspra99942 Apophis9P/Tempel 1ArrokothAsteroid BeltC/1995 O1 (Hale-Bopp)C/2020 F3 (NEOWISE)DinkineshKuiper BeltTrojan Asteroids
Earth satellites (3)
Stars, star systems, pulsars and black holes (48)
AldebaranAlgolAlpha CentauriAltairAntaresArcturusBarnard's StarBeta LyraeBeta PictorisBetelgeuseCanopusCapellaCastorCrab PulsarCygnus X-1DenebDG TauriFomalhautGaia BH1Gaia BH2Gaia BH3GemingaHH 211HH 30HH 46/47HL TauHulse-Taylor BinaryLalande 21185Lich (PSR B1257+12)Luyten 726-8PDS 70PolarisProcyonProxima CentauriPSR B1919+21PSR J0437-4715RigelRoss 154SiriusSpicaSS 433Tau CetiTW HydraeVegaVela PulsarW Ursae MajorisWolf 359Zeta Reticuli
Exoplanet systems (6)
Galaxies with observation-based destinations (14)
Nebulae with evidence models (44)
Boomerang NebulaBubble Nebula (NGC 7635)Butterfly Nebula (NGC 6302)California NebulaCarina NebulaCat's Eye NebulaCone NebulaCrescent NebulaDumbbell NebulaEagle NebulaEgg NebulaElephant’s Trunk NebulaFlame NebulaHeart NebulaHelix NebulaHomunculus NebulaHorsehead NebulaIris NebulaJewel Bug NebulaLagoon NebulaLobster NebulaMonkey Head NebulaNGC 2392NGC 3603NGC 602NGC 604North America NebulaPelican NebulaR AquariiRed RectangleRho OphiuchiRing NebulaRosette NebulaSaturn NebulaSkull NebulaSoul NebulaSouthern Ring NebulaThor’s Helmet NebulaTrifid NebulaTwin Jet NebulaV838 MonocerotisWesterlund 2Wizard NebulaWolf–Rayet 140
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.