# NASA Earth imagery for Earth from Space (preview)

Downloaded 2026-10-06. Every raster used by this page is NASA public-domain Earth science imagery, processed locally. No third-party textures or AI-generated imagery are used. Original downloads and SHA-256 manifest are retained in `/mnt/f/LessAngry/earth-14470/downloads/` (not published).

## Day surface — Blue Marble Next Generation, October 2004

- Official dataset and credits: https://science.nasa.gov/earth/earth-observatory/blue-marble-next-generation/base-map/
- NASA dataset explanation: https://earthobservatory.nasa.gov/ContentFeature/BlueMarble/bmng.pdf
- Eight official originals: `https://assets.science.nasa.gov/content/dam/science/esd/eo/images/bmng/bmng-base/october/world.200410.3x21600x21600.{A1,B1,C1,D1,A2,B2,C2,D2}.jpg` (each bracketed name is a separate file).
- Each original: 21,600 × 21,600 pixels. Global native grid: 86,400 × 43,200, nominal 500 m; MODIS on NASA Terra/Aqua, NASA Earth Observatory, Reto Stöckli and Robert Simmon. NASA-produced composite, with no third-party copyright notice on the source item.
- Local processing: decode at half resolution; three equirectangular levels at 10,800 × 5,400; 21,600 × 10,800; 43,200 × 21,600. Each tile covers 540 × 540 source texels plus a 2-texel filtering gutter (544 × 544 WebP, quality 88). No sharpening or invented detail. Equatorial spacing: 3.7065, 1.8532, **0.9266 km/texel**, respectively; east–west spacing decreases with latitude. The 2,048 × 1,024 startup WebP is a downsample of the same eight originals.
- These are historical monthly cloud-free composites, not live satellite photographs. The selected month matches the development month but does not change season automatically.

## Clouds — NASA Blue Marble cloud mosaic

- Official source item: https://visibleearth.nasa.gov/images/57747/blue-marble-clouds (legacy NASA item; may redirect to the Earth Observatory index).
- Startup original remains https://eoimages.gsfc.nasa.gov/images/imagerecords/57000/57747/cloud_combined_2048.jpg, 2,048 × 1,024; unchanged luminance WebP quality 85.
- Native NASA originals: `https://eoimages.gsfc.nasa.gov/images/imagerecords/57000/57747/cloud.{W,E}.2001210.21600x21600.png`, each **21,600 × 21,600**, 8-bit grayscale. West then east form a **43,200 × 21,600** equirectangular mosaic, **0.9266 km/texel** at the equator, exactly aligned with the finest day grid. Historical 2001 mosaic; NASA Goddard Space Flight Center, Reto Stöckli; enhancements by Robert Simmon. No live-weather claim.
- Reproduce with `python3 scripts/earth-cloud-assets.py --work ../clouds-work --evidence ../evidence/clouds`. Global two-texel gutters wrap longitude (including the NASA half boundary and dateline) and extend pole rows. Two levels only: 800 tiles at 21,600 × 10,800 (1.8532 km/texel) and 3,200 at native 43,200 × 21,600; 540 source texels plus gutters per tile, 544 × 544 luminance WebP quality 88. The native PNGs omit thermal polar clouds present in the combined startup image. Per tile, add the bilinearly sampled startup opacity minus a 2,048 × 1,024 Lanczos downsample of the native mosaic; clamp to 8-bit range. This preserves the existing coarse cloud coverage and brightness while transferring native fine detail, with no sharpening or fabricated detail. Polar regions without native observations retain the original coarse thermal clouds; their effective detail remains limited by that source. Treat grayscale as linear opacity, matching the startup shader.
- Seam repair (2026-10-07): verified original PNG bytes/SHA-256 show content discontinuities at both 180° and 0°; they predate tiling and low-frequency calibration. For the audited 180° native row 20, mean differences are 28.9981/255 in the original, 28.9944 after calibration and 28.4852 in the old encoded tile pair. This is an original mosaic boundary; the audit does not establish different acquisition times for the two halves. Add a compact C2 opacity feather after calibration, restricted to **8 native pixels per side** (4 pixels at level 2, 8 at level 3; total native band 16 pixels, about 14.83 km at the equator). Each row brings its two endpoint values to their midpoint; a quintic weight falls to zero at the outer edge. No spatial convolution or global blur is used. Shared longitude gutters copy the repaired neighbour texels. Incremental repair: `python3 scripts/earth-cloud-assets.py --seams-only --seam-width-native 8 --evidence ../evidence/merge/cloud-seams`. Only adjacent seam columns are visited; **239** changed WebP tiles use lossless encoding so every decoded RGB pixel outside the narrow band stays byte-for-byte identical, and all **3,761** other cloud tile files stay untouched. The full generator performs the same final seam step. The cloud tile manifest records the mixed encoding and band width. Original/native/calibrated comparisons, changed-file list, sizes and hashes are retained under `evidence/merge/cloud-seams/`; original PNGs are deleted after verification.
- The cloud sphere remains at the existing radius 1.0016 (about 10 km above the surface), with unchanged lighting and opacity. Visible cloud patches stream below 9,000 km; the native level is used below 1,500 km. The low map is masked under resident patches rather than accumulating opacity. Newly loaded patches fade over 0.6 seconds; missing-neighbour boundaries blend back to the startup map; neighbouring native patches share genuine source gutters and mesh edges. Mipmap/anisotropic filtering suppresses grazing-angle shimmer. Phones hold at most 24 cloud patches (36.1 MiB of RGBA texture storage including mipmaps), desktops 64; two concurrent abortable requests, with ImageBitmap/texture/geometry disposal on eviction.
- Original PNGs are removed after successful verification to save disk space; original byte sizes, URLs and SHA-256 are retained in `/mnt/f/LessAngry/earth-14470/evidence/clouds/source-sha256.json` (not published).

## Night lights — Black Marble 2016

- Official dataset: https://science.nasa.gov/earth/earth-observatory/earth-at-night/maps/
- Official explanatory item: https://science.nasa.gov/earth/earth-observatory/night-light-maps-open-up-new-applications-90008/
- Original: https://assets.science.nasa.gov/content/dam/science/esd/eo/images/imagerecords/144000/144898/BlackMarble_2016_3km.jpg
- Original resolution: 13,500 × 6,750 (nominal 3 km). NASA Earth Observatory; Joshua Stevens; Suomi NPP VIIRS; Black Marble data by Miguel Román, NASA Goddard. NASA-produced 2016 annual composite, no third-party copyright notice.
- Local processing: 2,048 × 1,024 startup and 4,096 × 2,048 detail WebP, quality 88. Shader suppresses the composite's dim land background and emits lights only on the actual night side. Desktop night lights have 9.77 km equatorial texture spacing at the published detail level. Phones use the 2,048 × 1,024 map (19.55 km/texel) to keep overlay GPU memory bounded; they do not download the larger night map. At altitudes below 9,000 km, both phones and desktops additionally stream only visible night-side native-resolution patches: 20 × 10 tiles, each 675 × 675 original texels plus 2-texel gutters, 679 × 679 WebP quality 90. This preserves the original 13,500 × 6,750 grid (2.9652 km equatorial spacing) without upscaling. No artificial sharpening or city detail is added. Global low-resolution emissions are masked where a native patch is resident, avoiding duplicate glow. Phone native night patches are capped at 8, desktop at 24, independently evicted. Neither the global maps nor the native night grid has the day surface's 0.93 km resolution.

## License and attribution

NASA content, including texture maps, generally is not subject to copyright in the United States and may be used on websites and in computer graphical simulations, with NASA attribution; no endorsement is implied. These selected NASA scientific composites carry no third-party copyright markings. NASA logos and protected third-party media are excluded.

Official NASA guidance: https://www.nasa.gov/nasa-brand-center/images-and-media/
NASA SVS public-domain statement: https://svs.gsfc.nasa.gov/help/

Atmospheric glow and ocean glint are procedural shaders, not additional image assets. They are restrained approximations; no metric elevation data or topographic displacement is claimed. Earth is a mean-radius sphere (6,371 km).

## R1 reference and distance checks (not additional site textures)

NASA's DSCOVR/EPIC full-day Earth photograph and Expedition 23 horizon
photograph are downloaded only outside the repository in
`../downloads/r1-reference/`; original URL, size, SHA-256 and NASA credit are
in its `SOURCE.md` and `manifest.json`. These are evidence references only.

- EPIC (NASA, 6 July 2015): https://www.nasa.gov/image-article/nasa-captures-epic-earth-image/
- ISS horizon (Expedition 23 Crew, NASA): https://apod.nasa.gov/apod/ap100623.html
- Webb / L2 distance: https://science.nasa.gov/mission/webb/orbit/
- Mean Sun distance and 8 minutes 20 seconds light time: https://science.nasa.gov/mission/voyager/voyager-1/voyager-1-what-is-a-light-day/
- Saturn minimum Earth distance 1205.5 million km, rounded to about 1.2 billion: https://nssdc.gsfc.nasa.gov/planetary/factsheet/saturnfact.html

## R4 — original NASA spacecraft views back toward Earth

Downloaded from the official NASA Science Photojournal pages below on
2026-10-06. The published JPEGs are byte-for-byte copies of the downloads:
no changed pixels, recoloring, sharpening, recompression, or added annotations.
Small cards crop the originals using CSS; a separate CSS circle marks Earth.
Opening a card displays the complete original frame. Images have no initial
`src` and load only when their corresponding distant landmark is approached.
Together the three originals total 169,166 bytes; each is below 300 KB.
File metadata and SHA-256 values are also recorded in `photos/SOURCE.json`.

### MESSENGER — PIA13474, Earth and Moon from 114 Million Miles

- Legacy official catalog: https://photojournal.jpl.nasa.gov/catalog/PIA13474
- Current official page: https://science.nasa.gov/photojournal/earth-and-moon-from-114-million-miles/
- Original file: https://assets.science.nasa.gov/content/dam/science/psd/photojournal/pia/pia13/pia13474/PIA13474.jpg
- Taken **2010-05-06**, from approximately **183 million km**. The Sun-distance landmark itself remains 150 million km; the photograph caption explicitly reports its different shooting distance.
- Credit: **NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington**; abbreviated on the small card to NASA/JHUAPL/CIW.
- Published file: `photos/PIA13474.jpg`, **1018 × 1024**, **95,174 bytes**.
- SHA-256: `beefe6d17c3ba3530c947044f127d311db442640013da4eaddcee26fd13088d4`.
- Earth is the brighter point on the left; the Moon is just to its right. Card crop: x=179, y=735, width=210, height=70 in original pixels. Independent Earth marker: x=284, y=770.

### Cassini — PIA17171, The Day the Earth Smiled (Sneak Preview)

- Legacy official catalog: https://photojournal.jpl.nasa.gov/catalog/PIA17171
- Current official page: https://science.nasa.gov/photojournal/the-day-the-earth-smiled-sneak-preview/
- Original file: https://assets.science.nasa.gov/content/dam/science/psd/photojournal/pia/pia17/pia17171/PIA17171.jpg
- Taken **2013-07-19**, from approximately **1.44 billion km** (898 million miles), in natural color.
- Credit: **NASA/JPL-Caltech/Space Science Institute**.
- Published file: `photos/PIA17171.jpg`, **838 × 958**, **43,808 bytes**.
- SHA-256: `323c80ea2e425b8717e14fd24df150ed6ba020b1280288058168daa26ff2a2dc`.
- Earth is the blue point below the rings; the Moon is the fainter protrusion on its right. Card crop: x=478, y=452, width=264, height=88. Independent Earth marker: x=610, y=496.
- R4 changes the Saturn landmark from the R1 minimum-distance example to this specific Cassini observation at **1,440,000,000 km**. Its short label remains “Saturn” in each language.

### Voyager 1 — PIA00452, original Pale Blue Dot

- Legacy official catalog: https://photojournal.jpl.nasa.gov/catalog/PIA00452
- Current official page: https://science.nasa.gov/photojournal/solar-system-portrait-earth-as-pale-blue-dot/
- Original file: https://assets.science.nasa.gov/content/dam/science/psd/photojournal/pia/pia00/pia00452/PIA00452.jpg
- Taken **1990-02-14**, from **more than 6 billion km**. This is PIA00452, not the 2020 reprocessing. NASA describes Earth in the original observation as a crescent only **0.12 pixel** in size; this refers to the observation, not the size of a rescaled website image.
- Credit: **NASA/JPL-Caltech**.
- Published file: `photos/PIA00452.jpg`, **453 × 614**, **30,184 bytes**.
- SHA-256: `5209d4860851d82d9612744b9c141d4e8abc58317b31ca6bb685077d3af745bc`.
- Card crop: x=254, y=314, width=180, height=60. Independent Earth marker: x=344, y=344, in the sunlight streak.

### Card enlargement and unresolved Earth (merge revision, 2026-10-07 CST)

The corner label now compares the card’s angular sampling with this page’s view: `pageDegPerCssPx = VERTICAL_FOV_DEG / canvasCssHeight`, `cardDegPerCssPx = jpegDegPerPx / factor`, and `N = pageDegPerCssPx / cardDegPerCssPx`, where `factor = displayedJpegCssWidth / jpegFileWidth`. The existing vertical FOV is 45°. Both the card and canvas are observed for resizing; DPR is not multiplied in. Values below 10 use one decimal, values at least 10 use an integer. This is an approximate angular enlargement, not the ratio of an exposed spot’s diameter to the page’s minimum-size point. The full-image dialog still shows the entire original JPEG.

Subpixel claims below refer to the original instrument observation, not the displayed JPEG. For the independent sanity calculation, use Earth's mean diameter 12,742 km, angular diameter `2 asin(6371 / distanceKm)`, and approximate camera sample angle `FOV radians / detector width`. These calculations are geometric inferences from the official camera specifications and distances, not quoted measured spot widths. Binning would only make the Earth smaller in sensor-pixel units.

- **MESSENGER PIA13474:** the [official item](https://science.nasa.gov/photojournal/earth-and-moon-from-114-million-miles/) identifies the **Wide Angle Camera**, 10.5° FOV, distance 183,000,000 km and 10-second exposures. Its metadata instrument link is mislabeled “WAC (Narrow Angle Camera)”; the description and acquisition block explicitly say Wide Angle Camera. The [JPL PDS MDIS specification, Table 2-1](https://planetarydata.jpl.nasa.gov/img/data/messenger/MSGRMDS_2001/DOCUMENT/MDIS_CDR_RDRSIS.HTM) specifies the WAC's 10.5° FOV and 1024×1024 detector. Angular diameter ≈69.63 μrad; sample angle ≈178.96 μrad; diameter ≈**0.389 sensor pixel**, safely below one. No specific computed decimal is shown in the card.
- **Cassini PIA17171:** the [official item](https://science.nasa.gov/photojournal/the-day-the-earth-smiled-sneak-preview/) identifies the **Wide Angle Camera**, distance 1,445,858,000 km, Earth image scale **86,620 km/pixel**, and explicitly says Earth's illuminated area is unresolved: its dot has the response size of a comparably bright point source. The [JPL ISS calibration report, instrument description](https://planetarydata.jpl.nasa.gov/img/data/cassini/cassini_orbiter/coiss_0001/document/report/iss/1.0/1.0_introduction.htm) specifies WAC **3.5°×3.5°** FOV and **1024×1024** detector. FOV geometry gives ≈**0.148 sensor pixel**; the official linear sample scale gives `12742/86620` ≈**0.147**. Both support “less than one sensor pixel.” This is the WAC image, not the accompanying NAC composite.
- **Voyager PIA00452:** the [official item](https://science.nasa.gov/photojournal/solar-system-portrait-earth-as-pale-blue-dot/) directly states **0.12 pixel** in the original observation, and explains scattered sunlight and image magnification artifacts. No new camera-based numeric estimate is substituted for NASA's value.

The brief eight-language card note explains local enlargement and that exposure/light spreading affect the visible spot size. The spot is not a resolved Earth disk whose bright footprint can be compared directly with the simulation's central point. No additional circle or camera mode was added to the simulation, and the original JPEG bytes are unchanged.

### Use conditions for the three photographs

The official item credits above are retained. These selected NASA planetary
science images carry no separate third-party copyright restriction on their
official item pages. NASA scientific imagery is generally public domain in the
United States; JPL's image-use policy permits credited use unless an item states
otherwise. No endorsement is implied and no NASA/JPL logo is included.

- JPL image-use policy: https://www.jpl.nasa.gov/jpl-image-use-policy/
- NASA images and media guidance: https://www.nasa.gov/nasa-brand-center/images-and-media/

The policies were read on the official websites. An optional attempt to save
the JPL policy with curl returned HTTP 403; the policy remained readable via
the browsing tool. All three required item pages and original JPEG downloads
returned HTTP 200, with the original response headers retained outside the
repository in `../downloads/r4-nasa/`.

### Verified publication sampling for the relative badge (2026-10-07 CST)

- **PIA17171 (numeric):** the [NASA item and its full JPEG download](https://science.nasa.gov/photojournal/the-day-the-earth-smiled-sneak-preview/) describe this released wide-angle view and specify **86,620 km/pixel at Earth** and **1,445,858,000 km distance**. The downloaded JPEG is the existing unmodified **838 × 958** product, not PIA17170’s enlarged close-up. Its approximate angular sample is `atan(86620 / 1445858000) × 180 / pi` degrees per published pixel. We use the scale supplied for this view; no separate detector-width or image-enlargement factor is assumed. [PIA17170](https://science.nasa.gov/photojournal/one-special-day-in-the-life-of-planet-earth-close-up/) explicitly has a fivefold enlargement and a different 8,662 km/pixel camera scale; neither belongs to our file.
- **PIA13474 (no number):** the [NASA caption](https://science.nasa.gov/photojournal/earth-and-moon-from-114-million-miles/) confirms the WAC’s **10.5°** FOV; [JPL PDS MDIS SIS, Table 2-1](https://planetarydata.jpl.nasa.gov/img/data/messenger/MSGRMDS_2001/DOCUMENT/MDIS_CDR_RDRSIS.HTM) confirms **1024 × 1024** detector pixels. `10.5 / 1024 = 0.01025390625°` is the candidate detector sampling. The stored official JPEG is **1018 × 1024**, but neither the caption nor the SIS explicitly establishes this published file’s crop/resampling mapping. SIS §2.1.8 documents four dark columns, which does not by itself explain six missing published columns. Equal height and a full-resolution download label alone are insufficient proof of unchanged sampling. Therefore `angularPixelDeg = null`; the eight-language badge says “Taken with a telephoto camera,” without a guessed N.
- **PIA00452 (no number):** [NASA’s exact 1990 product caption](https://science.nasa.gov/photojournal/solar-system-portrait-earth-as-pale-blue-dot/) explicitly identifies an enlarged image and attributes background artifacts to magnification, but gives **no numerical enlargement factor** for its **453 × 614** JPEG. The [NASA NSSDC Voyager instrument entry](https://nssdc.gsfc.nasa.gov/imgcat/html/object_page/vg1_p20938.html) provides **0.424° / 800 pixels = 0.00053° per detector pixel**. If the publication enlargement were `m`, the needed JPEG scale would be `0.00053 / m`; `m` is unverified. We do not treat the JPEG as an unresampled detector frame, nor borrow the 2020 PIA23645 dimensions. `angularPixelDeg = null`, so the badge has no N. The existing **0.12 detector pixel** statement and explanation of exposure/scattered light remain unchanged.