# Solar System texture attribution

Planet, Sun, Earth cloud and Saturn ring maps © Solar System Scope.
Source: https://www.solarsystemscope.com/textures/
License: Creative Commons Attribution 4.0 International, https://creativecommons.org/licenses/by/4.0/
Downloaded 2026-09-13. The original 2K texture files are unchanged. They are rendered with lighting, tone mapping, atmospheric effects, and ring projection in the interactive scene.

These are illustrative maps, not live planetary imagery. The source describes color adjustment and reconstructed/fictitious areas where coverage is missing.

Planet facts and orbital periods: NASA, https://science.nasa.gov/learn/basics-of-space-flight/chapter1-2/
The visualization independently compresses planet sizes and distances, circularizes orbits, composes initial positions, accelerates orbital time, and uses illustrative axial rotation speed. It is not an ephemeris or navigation tool.

## Current-time positions
NASA/JPL Horizons geometric vectors, Sun-centered, J2000 ecliptic/ICRF, UTC,
AU and AU/day. Four-hour position/velocity samples are distributed as monthly
files in `/ephemerides/`; cubic Hermite interpolation evaluates the device's
current UTC time. Coverage: 2026-01-01 through 2029-01-01. Refresh with
`scripts/export-solar-ephemerides.py` before coverage expires. Downloads are
sequential, cached locally, and never embedded NASA API requests from visitors.
Outside available coverage, the UI labels JPL's approximate 1800–2050 orbital
elements model. Earth in that fallback means the Earth–Moon barycenter.
This is not observer-specific apparent sky positioning. Distances and radii are
compressed independently. Orientation, surface longitude and cloud patterns
are illustrative. JPL is the data source, not an endorsement.

Moon texture: Solar System Scope, `2k_moon.jpg`, CC BY 4.0, same attribution above.
Neptune's shader reduces the old texture's saturated blue toward pale blue-green;
it is an illustrative correction, not a calibrated scientific image.
Reference: https://www.ox.ac.uk/news/2024-01-05-new-images-reveal-what-neptune-and-uranus-really-look-0