Catalogues and sources

All runtime data is hosted with the application. Import scripts clean source snapshots, normalise identifiers and units, validate references, create binary catalogues or spatial tiles, and update the versioned manifest before deployment.

Current coverage

Layer	Runtime coverage	Scientific treatment
Solar System	41 objects: Sun, planets, 21 moons, dwarf planets, asteroids, and comets	Local ephemerides and documented JPL orbital providers
Confirmed exoplanets	6,333 planets around 4,747 hosts	NASA composite catalogue facts; illustrative close-up systems
Stellar catalogue	10,000 selected HYG stars	Observed J2000 positions and velocities; bounded linear propagation over ±10,000 Julian years
Gaia stellar hierarchy	2,923,790 inputs; 133,526 measured-source samples	Calculated 512 pc aggregates; measured J2016.0 samples; incomplete background
Constellations	88 modern figures, 644 segments	Cultural line conventions mapped to HYG identifiers
Historical supernovas	6 events and remnants	Documented positions and dates; illustrative visual evolution
Local Group	31 galaxies	Catalogue positions with adapted morphology and size
Local Volume Database	102 Local Group dwarfs, 402 globular clusters, 241 dwarfs from 2.9 to 12.8 Mpc	Calculated positions and galactocentric velocities from LVDB measurements; illustrative points and close-up texture; 45 measured-motion arrows on request
Nearby Universe	720 galaxies	Static local-volume octree and catalogue-backed overview
2MRS galaxy field	42,788 galaxies beyond 11 Mpc; 5,203 illustrative zone-of-avoidance points	Calculated positions at group distance (Cosmicflows-4 when measured, otherwise Tully 2015 rescaled to the Cosmicflows-4 scale); illustrative fill never searchable
Cosmicflows-4	37,730 galaxy groups	Calculated three-dimensional positions from published catalogue fields
Large-scale structures	26,520 positionable detections	Separate cluster, supercluster, wall, basin, attractor, repeller, void, and filament products
Tempel filaments	15,421 spines and 275,599 points	Published spine geometry preserved in a compact binary layer

The Tempel binary is fetched and validated in a dedicated Web Worker at cosmic-web scale. Its six decoded typed-array buffers are transferred back without copying; browsers without Worker support use the same validated loader on the main thread.

The Local Volume Database layers add only objects the map did not already draw: 389 LVDB rows that match an editorial, Nearby Universe, 2MRS, or curated cluster object by name or position are dropped, and the existing object is kept unchanged. Local Group dwarfs appear at the Local Group scale (and around their host galaxy); the 204 Milky Way globular clusters replace the halo's illustrative clusters at the Milky Way scale, while clusters of other galaxies appear when their host is targeted; distant dwarfs appear at the Nearby Universe scale and are named around the targeted group, such as Centaurus A. The optional "Measured motions" layer draws, for the 45 galaxies whose 3D velocity passes a precision gate, the distance travelled in 500 million years at constant velocity: straight-line extrapolations, not orbits. Objects of uncertain nature (galaxy or star cluster) are labelled as such in their card.

The 20 named flow landmarks are not merged into the Tempel network: two walls retain their published representative extents, 15 probabilistic basins use the published Table 2 centres and probabilities, and attractor/repeller symbols mark reconstructed velocity-field extrema. Basin radii are equivalent display radii derived from published volumes, not observed spherical boundaries.

Principal sources

• Astronomy Engine for local planetary and lunar calculations;
• NASA/JPL satellite mean elements and physical parameters for major moons;
• NASA/JPL Small-Body Database for bundled dwarf planets, asteroids, and comets;
• NASA/JPL Solar System Simulator maps and USGS Astrogeology for locally hosted spacecraft surface mosaics;
• NASA VTAD planetary models for representative Saturn, Uranus, and Neptune atmosphere atlases;
• NASA/JPL-Caltech's Phobos and Deimos models, NASA VTAD's Ceres and Vesta models, NASA's Bennu 3D model, and ESA's 67P OSIRIS shape catalogue for deferred observed shapes;
• DAMIT model 4395 for Pallas and DAMIT model 4392 for Hygiea for quality-4 calculated shape reconstructions based on VLT/SPHERE observations;
• NASA/PDS shape products for Ceres and Vesta, spacecraft measurements for Halley's nucleus, and the Ortiz et al. 2017 stellar-occultation model for Haumea's triaxial body and ring;
• NASA Exoplanet Archive PSCompPars for confirmed exoplanets and hosts;
• HYG Database v4.1 for the compact stellar field;
• Gaia Data Release 3gaia_source_lite for the quality-filtered hybrid stellar background;
• Stellarium modern sky culture for constellation figures;
• McConnachie 2012 for Local Group galaxies;
• the Local Volume Database (Pace 2024, arXiv:2411.07424; release v1.1.1, CC0) for Local Group dwarfs, globular clusters, distant Local Volume dwarfs, and measured motions;
• the Updated Nearby Galaxy Catalog for local-volume galaxies;
• Cosmicflows-4 groups for the outer group layer;
• the 2MASS Redshift Survey groups of Tully 2015 and HyperLEDA common names for the 2MRS galaxy field;
• SDSS DR7 superclusters, BOSS DR12 voids, Planck PSZ2 clusters, and Tempel SDSS DR8 filaments for large-scale structures;
• NASA Visible Earth and other source-specific planetary imagery documented with each bundled texture.

Observed surface mosaics are used only where an appropriate global product is available. Filled gaps, processed color, and incomplete coverage remain part of the published cartography and are identified in the object card. Titan uses a Cassini ISS near-infrared mosaic; Saturn, Uranus, and Neptune use representative NASA model atlases explicitly marked illustrative. Phobos, Deimos, Ceres, Vesta, and Bennu have observed textured shapes; 67P has an observed shape with an illustrative neutral surface. Pallas and Hygiea use calculated shape reconstructions with illustrative untextured surfaces. Their polygonal assets are deferred until close LOD, with lightweight fallbacks during loading or failure. Haumea and Halley's nucleus preserve sourced axis ratios with triaxial silhouettes, while their adaptive volume remains stable across LODs. Other unresolved bodies keep explicitly procedural materials instead of receiving a misleading photographic skin.

The repository records detailed licences and transformations beside the static datasets and texture assets. Bundled third-party material remains subject to its original licence even though the application source is MIT licensed.

Static manifest

/data/manifest.json is the browser entry point. Every dataset declares an identifier, URL, type, and format where applicable. The loader validates JSON structures and binary headers before exposing data to the engine. A failed optional catalogue produces a development warning without corrupting unrelated layers.

Rebuilding data

The repository includes deterministic Node.js import commands for stars, exoplanets, nearby galaxies, constellations, Cosmicflows groups, cosmic volume, and published structures. Source snapshots are not part of the browser runtime.

cd client
npm run data:stars
npm run data:exoplanets
npm run data:nearby-galaxies
npm run data:cosmic-web
npm run data:cosmic-structures
npm run data:2mrs-names
npm run data:2mrs-galaxies
npm run data:local-volume
npm run test:data

Not every import should be run on each application build. Prepared versioned artefacts are committed and validated; import commands are used when intentionally refreshing a source snapshot.

Next: Performance and limits.