The authoritative registry lives in SECURITY.md (invariant 5: data
arrives with provenance settled first). This page is the readable summary;
if the two ever disagree, SECURITY.md wins and this page has a bug.
| Dataset | Source | Licence | Where |
|---|---|---|---|
| Terrain | Environment Agency LIDAR Composite DTM 2022, 1 m bare earth, via Defra’s WCS | Open Government Licence v3 — © Environment Agency copyright and/or database right 2022 | salisbury-plain.heightfield, baked by scripts/bake_terrain.py |
| Star catalogue | Hipparcos, ESA SP-1200 (CDS I/239) | Free with attribution | hipparcos-bright.csv (8,870 stars, V ≤ 6.5) |
| Star names | IAU-CSN (WGSN, E. Mamajek) | Official IAU nomenclature, freely published | generated into StarCatalog.properNames |
| Constellation figures | Authored in-repo — no external figure set consulted | Ours | ConstellationLines.swift, generated by script |
| Planetary theory | VSOP87D (CDS VI/81), truncated | Free scientific data | VSOP87Tables.swift, generated |
| Moon colour map | NASA SVS CGI Moon Kit (LRO) | Public domain | moon-albedo.jpg |
| Surface textures | ambientCG Rock030 / Grass004 | CC0 1.0 | engine resource bundle |
| Sky model | Preetham et al. 1999 | Published formula, no data vendored | implemented in MSL |
| Algorithms | Meeus; Espenak & Meeus ΔT | Published methods, cited | implemented in HengeAstro |
| Milky Way | NASA SVS Deep Star Maps 2020 (SVS 4851), from Gaia DR2 | Public domain; credit NASA/GSFC SVS and ESA/Gaia/DPAC | milkyway-2020.jpg, 2048×1024 |
Declined or waiting on licence: Hosek–Wilkie sky data, any recorded ambient sound, Stellarium-style constellation datasets (mooted by drawing our own), H. A. Rey figure drawings (same).
Rule of the house: no dataset enters the repo before its licence is written down here, and the first third-party code dependency is a stop-and-ask.