{
  "prepared_utc": "2026-10-19T03:49:23.911751+00:00",
  "projection": "Global equirectangular, 2:1 aspect ratio, north at top; source pixels kept in original orientation",
  "usage": "Day images: sRGB map. Cloud images: grayscale alphaMap with NoColorSpace, not a precolored cloud photograph. Both layers use identical equirectangular UV convention.",
  "sources": {
    "day": {
      "source_page": "https://science.nasa.gov/earth/earth-observatory/blue-marble-next-generation/base-map/",
      "documentation_url": "https://science.nasa.gov/earth/earth-observatory/blue-marble-next-generation/",
      "download_url": "https://assets.science.nasa.gov/content/dam/science/esd/eo/images/bmng/bmng-base/july/world.200407.3x21600x10800.jpg",
      "source_filename": "world.200407.3x21600x10800.jpg",
      "expected_dimensions": [
        21600,
        10800
      ],
      "credit": "NASA Earth Observatory; Blue Marble: Next Generation by Reto Stoeckli (NASA/GSFC)",
      "scientific_context": "July 2004 Blue Marble Next Generation satellite-data color composite, predominantly Terra MODIS. NASA visualization processing and cloud removal are already in the source; this is not one exposure, current imagery, or calibrated surface reflectance. Base map without added topographic/bathymetric shading.",
      "original_dimensions": [
        21600,
        10800
      ],
      "original_mode": "RGB",
      "original_format": "JPEG",
      "source_sha256": "dea8b4dc8a4f93f5f8bce0c8c85a508a178e7901e9ed8e6bf86e6ce7ef6d61e2",
      "source_bytes": 21125326,
      "outputs": [
        {
          "file": "day-8k.jpg",
          "dimensions": [
            8192,
            4096
          ],
          "mode": "RGB",
          "bytes": 4505203,
          "sha256": "39e1c17eb6f4c4d0ed0854068e086675d725d7b8ece71ec4679c2a18c8403559",
          "processing": "Decode NASA JPEG to RGB, resize with Lanczos, JPEG encode. No recoloring, sharpening, generated detail, or upsampling.",
          "encoding": "JPEG quality=92, chroma subsampling=0, optimize=true, progressive=true"
        },
        {
          "file": "day-4k.jpg",
          "dimensions": [
            4096,
            2048
          ],
          "mode": "RGB",
          "bytes": 1267916,
          "sha256": "1636684154dea20179e39c0d46d657b305a23e511174312515931ab83ad4e613",
          "processing": "Decode NASA JPEG to RGB, resize with Lanczos, JPEG encode. No recoloring, sharpening, generated detail, or upsampling.",
          "encoding": "JPEG quality=92, chroma subsampling=0, optimize=true, progressive=true"
        },
        {
          "file": "day-2k.jpg",
          "dimensions": [
            2048,
            1024
          ],
          "mode": "RGB",
          "bytes": 362619,
          "sha256": "8668cc9d3e30b1fe9f63ecb5f37d1d0ae8f11c4b0d1cc5370c765685ecdf2438",
          "processing": "Decode NASA JPEG to RGB, resize with Lanczos, JPEG encode. No recoloring, sharpening, generated detail, or upsampling.",
          "encoding": "JPEG quality=92, chroma subsampling=0, optimize=true, progressive=true"
        }
      ]
    },
    "clouds": {
      "source_page": "https://visibleearth.nasa.gov/images/57747/blue-marble-clouds/77558l",
      "documentation_url": "https://svs.gsfc.nasa.gov/3525/",
      "download_url": "https://eoimages.gsfc.nasa.gov/images/imagerecords/57000/57747/cloud_combined_8192.tif",
      "source_filename": "cloud_combined_8192.tif",
      "expected_dimensions": [
        8192,
        4096
      ],
      "credit": "NASA Goddard Space Flight Center; clouds by Reto Stoeckli, compositing by Robert Simmon; MODIS Atmosphere Group",
      "scientific_context": "Blue Marble Clouds, published February 11, 2002: two days of visible-light cloud imagery plus a third day of thermal infrared imagery over the poles. Historical composite, not contemporaneous with the day map or live weather. Brightness used as visual opacity is not calibrated cloud optical depth.",
      "source_page_note": "Legacy Visible Earth page may redirect following NASA site migration; original NASA/GSFC TIFF download remains available. NASA SVS 3525 independently documents use of original 2002 Blue Marble cloud data.",
      "original_dimensions": [
        8192,
        4096
      ],
      "original_mode": "RGB",
      "original_format": "TIFF",
      "source_sha256": "d137775d8966ab8d443fd5126dc6e7ad72072bc1ed50555c5818d221735daf0f",
      "source_bytes": 35870468,
      "rgb_channels_identical": true,
      "alpha_range": [
        0,
        255
      ],
      "outputs": [
        {
          "file": "clouds-4k.jpg",
          "dimensions": [
            4096,
            2048
          ],
          "mode": "L",
          "bytes": 2779131,
          "sha256": "8f32b638262e7c952c4f65e4f8147a30f82f4c1ad7d7e68770378abdec58edb8",
          "processing": "Extract identical RGB grayscale channel, resize with Lanczos, JPEG encode. White clouds / black clear sky, intended as alphaMap with NoColorSpace. No threshold, contrast, gamma or invented clouds.",
          "encoding": "JPEG quality=92, chroma subsampling=0, optimize=true, progressive=true"
        },
        {
          "file": "clouds-2k.jpg",
          "dimensions": [
            2048,
            1024
          ],
          "mode": "L",
          "bytes": 766139,
          "sha256": "0babd21ed87e1343326a0562e14dc15d5946a9ca7c9cfc66464304cfa8c875be",
          "processing": "Extract identical RGB grayscale channel, resize with Lanczos, JPEG encode. White clouds / black clear sky, intended as alphaMap with NoColorSpace. No threshold, contrast, gamma or invented clouds.",
          "encoding": "JPEG quality=92, chroma subsampling=0, optimize=true, progressive=true"
        }
      ]
    }
  }
}