{
  "retrieved": "2026-10-25",
  "notes": [
    "NASA 3D Resources describes its assets as free to download and use subject to NASA media guidelines.",
    "NASA VTAD textures are rendering resources; source pages do not specify instrument or acquisition epoch.",
    "Scene lighting, axial orientation, cloud animation, filled polar regions and stellar surfaces are illustrative renderer choices."
  ],
  "assets": [
    {
      "id": "mars",
      "file": "assets/mars-color.jpg",
      "title": "Mars Image Texture",
      "credit": "NASA/Jet Propulsion Laboratory & Caltech; Viking imagery processed by USGS",
      "url": "https://science.nasa.gov/3d-resources/mars/",
      "download": "https://assets.science.nasa.gov/content/dam/science/cds/3d/resources/image/mars/Mars.jpg",
      "projection": "equirectangular",
      "adaptation": "Original image, unchanged. Historical Viking composite, not a current observation.",
      "width": 1440,
      "height": 720,
      "bytes": 972896,
      "sha256": "12ec6bf02ebd42a246edc778cb2ce8c595b4d9f0892badf0bfff8abb2303c780",
      "license": "NASA images and media usage guidelines; source credit retained; no NASA endorsement implied",
      "licenseUrl": "https://www.nasa.gov/nasa-brand-center/images-and-media/"
    },
    {
      "id": "jupiter",
      "file": "assets/jupiter-color-2025.jpg",
      "title": "Hubble OPAL Cycle 32 Jupiter global map, 2025 rotation A",
      "credit": "NASA, ESA, A. A. Simon, M. H. Wong",
      "url": "https://archive.stsci.edu/hlsp/opal/opal-jupiter-cycle-32",
      "download": "https://archive.stsci.edu/missions/hlsp/opal/cycle32/jupiter/hlsp_opal_hst_wfc3-uvis_jupiter-2025a_f395n-f502n-f631n_v1_globalmap.tif",
      "projection": "Cylindrical map, planetographic latitude; System III west longitude decreases to the right",
      "adaptation": "Official RGB TIFF converted to JPEG quality 94 without chroma subsampling; no color or contrast adjustment. Renderer fills unobserved polar caps by extending neighboring latitude colors. See notes and data/observations/jupiter.json.",
      "width": 3600,
      "height": 1800,
      "bytes": 1411438,
      "sha256": "7b76346a32bbd1bda469fffa635843488a56e4f85714268adb35e87e6e1027c3",
      "license": "CC BY 4.0",
      "licenseUrl": "https://creativecommons.org/licenses/by/4.0/",
      "notes": "Observed 2025-12-11 07:24:09–15:40:10 UTC. Official three-visible-filter RGB display product, not calibrated naked-eye color. Original encoded as JPEG without color adjustments. Shader converts parametric latitude to planetographic latitude on the oblate spheroid, clamps UV latitude to 0.065–0.945 for missing polar coverage; polar extension is illustrative. Source file retained in observation-research/jupiter outside the published site."
    },
    {
      "id": "saturn",
      "file": "assets/saturn-color.jpg",
      "title": "Saturn 3D Model — surface texture",
      "credit": "NASA Visualization Technology Applications and Development (VTAD)",
      "url": "https://science.nasa.gov/resource/saturn-3d-model/",
      "download": "https://assets.science.nasa.gov/content/dam/science/psd/solar/2023/09/s/Saturn_1_120536.glb",
      "projection": "equirectangular",
      "adaptation": "Extracted saturn_diff.jpg PNG texture from the official GLB; reprojected its cube atlas using model positions and UVs into a 2048×1024 sphere map, with bilinear sampling, then JPEG quality 92. Visualization texture: exact observing epoch and image provenance unspecified by source. Not suitable for precise longitude identification.",
      "width": 2048,
      "height": 1024,
      "bytes": 269624,
      "sha256": "43cc90ddbcb8ae95e69ef468b3627584687c3b4541e60e6db59251df8cb5cf92",
      "license": "NASA images and media usage guidelines; source credit retained; no NASA endorsement implied",
      "licenseUrl": "https://www.nasa.gov/nasa-brand-center/images-and-media/"
    },
    {
      "id": "saturn-rings",
      "file": "assets/saturn-rings.png",
      "title": "Saturn 3D Model — ring color and opacity strip",
      "credit": "NASA Visualization Technology Applications and Development (VTAD)",
      "url": "https://science.nasa.gov/resource/saturn-3d-model/",
      "download": "https://assets.science.nasa.gov/content/dam/science/psd/solar/2023/09/s/Saturn_1_120536.glb",
      "projection": "radial strip, RGBA",
      "adaptation": "Extracted unchanged from the official GLB image saturn_rings_25sat_outterRings.png. u=0 corresponds to inner radius 1.2323; u=1 to outer radius 2.3309, in planet equatorial radii. Sample v=0.5. Original transparency retained.",
      "width": 4096,
      "height": 16,
      "bytes": 9615,
      "sha256": "d4ddbcd796869bd3f8508252da4fd284c4195cd0f06c02294f6c918b568ba1c7",
      "license": "NASA images and media usage guidelines; source credit retained; no NASA endorsement implied",
      "licenseUrl": "https://www.nasa.gov/nasa-brand-center/images-and-media/"
    },
    {
      "id": "earth-clouds",
      "file": "assets/earth-clouds.jpg",
      "title": "Blue Marble: Clouds (2002)",
      "credit": "NASA Goddard Space Flight Center; image by Reto Stöckli; enhancements by Robert Simmon; MODIS science teams",
      "url": "https://visibleearth.nasa.gov/images/57747/blue-marble-clouds/77558l",
      "download": "https://eoimages.gsfc.nasa.gov/images/imagerecords/57000/57747/cloud_combined_2048.jpg",
      "projection": "equirectangular, grayscale cloud luminance",
      "adaptation": "Original 2048×1024 JPEG retained unchanged. Use luminance as a cloud opacity mask on a separate white sphere slightly above the Earth surface. Historical composite from two days of visible-light imagery plus polar thermal-infrared imagery; not current weather. The original Visible Earth page currently redirects to Earth Observatory, but NASA image download remains available.",
      "width": 2048,
      "height": 1024,
      "bytes": 829367,
      "sha256": "daddaad84d7a33bbbc86cdda3f591099f57cee8607b7bcf3b67eb7e4f7a1c793",
      "license": "NASA images and media usage guidelines; source credit retained; no NASA endorsement implied",
      "licenseUrl": "https://www.nasa.gov/nasa-brand-center/images-and-media/"
    },
    {
      "file": "assets/mercury-color.jpg",
      "title": "MESSENGER MDIS global LOI grayscale mosaic, 4K",
      "credit": "NASA / JHUAPL / Carnegie Institution of Washington",
      "url": "https://trek.nasa.gov/mercury/",
      "notes": "2011–2015 mission imagery; LOI map released 2016. NASA Trek tiles stitched and encoded as JPEG, no artificial craters or relief. Detailed manifest: data/observations/mercury.json",
      "sha256": "554453bc7c27ca9808a6a3c50e4d3dfa3028e1a28a963a16781a800dc19859b2",
      "id": "mercury",
      "width": 4096,
      "height": 2048,
      "bytes": 4564935,
      "license": "NASA Images and Media Usage Guidelines",
      "licenseUrl": "https://www.nasa.gov/nasa-brand-center/images-and-media/"
    }
  ]
}