# 当前地球动态与素材来源 / Current Earth visual and sources

首页使用一个球体的创意合成：将已确认的明亮原图可见球面投影到球体上，转向原图未包含的区域时，以 NASA 历史全彩地球与云层、城市灯光素材补足。球体持续单向缓慢转动，360 秒一圈。原图的白云、海洋和灯光在已拍摄区域保留原有 RGB；未包含区域使用带有真实历史云纹的全彩贴图，没有程序噪声云块或镜像背面。

This is a creative, single-sphere composite. The approved bright artwork is projected onto its observed portion of the sphere; NASA historical full-color Earth/cloud imagery and city-light imagery fill regions absent from that artwork. The sphere turns in one direction once every 360 seconds. It is not live satellite imagery, current weather, or an exact geographically registered reconstruction of the original creative artwork.

## 原版创意图 / Approved artwork

- File: `earth-orbit-bright-original.png` (1672 × 941).
- The PNG is an exact byte copy of the previously approved bright digital brand artwork, not an additional NASA photograph.
- SHA256: `668DCEAC74F57EA10C911DBAFAC147DB9AA297E3C03BF3CD9C094B44FE2C375A`.

## 当前未包含区域的全彩与云层 / Active unseen-region color and clouds

NASA Blue Marble 2002: Land Surface, Ocean Color, Sea Ice and Clouds. Credit: NASA Goddard Space Flight Center; image by Reto Stöckli (land surface, shallow water and clouds), enhancements by Robert Simmon (ocean color and compositing). The source is a historical composite of observations, not current cloud/weather data.

- Source article: https://science.nasa.gov/earth/earth-observatory/the-blue-marble-true-color-global-imagery-at-1km-resolution/
- Official TIFF downloaded and verified on 2026-10-16: https://eoimages.gsfc.nasa.gov/images/imagerecords/57000/57735/land_ocean_ice_cloud_8192.tif
- Verified source: 8192 × 4096, 51,115,006 bytes; retained as `earth-cloud-day-nasa-8192.tif`.
- Web derivatives: `earth-cloud-day-8k.webp` (8192 × 4096), `earth-cloud-day-4k.webp` (4096 × 2048) and `earth-cloud-day-2k.webp` (2048 × 1024). Lanczos3 resize where needed, WebP quality 94 / 94 / 93. The renderer selects 8K on capable desktop devices, with 4K and 2K fallback.
- Natural full-color detail is retained. The shader uses bright artistic illumination, not a dark monochrome map grade.

## 城市灯光 / City lights

NASA Earth Observatory Black Marble 2016. Imagery by Joshua Stevens using Suomi NPP VIIRS data provided by Miguel Román / NASA GSFC.

- Source page: https://science.nasa.gov/earth/earth-observatory/earth-at-night/maps/
- Initial official delivery: https://assets.science.nasa.gov/dynamicimage/assets/science/esd/eo/images/imagerecords/144000/144898/BlackMarble_2016_01deg.jpg?w=3600&h=1800&fit=clip&crop=faces%2Cfocalpoint
- Higher-size official delivery: https://assets.science.nasa.gov/dynamicimage/assets/science/esd/eo/images/imagerecords/144000/144898/BlackMarble_2016_01deg.jpg?w=8192&h=4096&fit=clip&crop=faces%2Cfocalpoint
- Higher-size delivered JPEG verified as 8192 × 4096; delivery size does not establish underlying sensor/native resolution.
- `earth-night-4k.webp`: 4096 × 2048, Lanczos3/WebP quality 96. Existing 2K version remains a fallback. Small glow sampling uses actual loaded texture dimensions.

## 保留的旧版素材 / Retained earlier-version material

The earlier cloud-free December 2004 Blue Marble Next Generation day textures remain in the source archive for rollback but are not the active unseen-region day material.

- Original source page: https://science.nasa.gov/earth/earth-observatory/blue-marble-next-generation/base-topography-bathymetry/
- Original by Reto Stöckli: https://assets.science.nasa.gov/content/dam/science/esd/eo/images/bmng/bmng-topography-bathymetry/december/world.topo.bathy.200412.3x5400x2700.jpg
- Retained 2K and 4K encodings derive from the same 5400 × 2700 source.

The render's atmosphere, sunlight, geographic registration and rotation are artistic website presentation. No NASA logo, affiliation, endorsement or certification is claimed.

Media guidelines: https://www.nasa.gov/nasa-brand-center/images-and-media/