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H.O.T EARTH

Data sources

Every world is backed by real, public data. This page is the index; each world also ships a *_DATA_SOURCES.md in the repository’s docs/ folder with the exact URLs, credit lines, and verification dates.

Earth and near-Earth

Section titled “Earth and near-Earth”
Data Source License
Daily satellite imagery NASA GIBS Public domain
Weather and point forecasts Open-Meteo Free, open (CC BY 4.0 for data)
Global wind field (GFS) NOAA Public domain
ISS orbital elements (TLE) CelesTrak / public TLE Public domain data
City lights (Black Marble) NASA Public domain

Solar System

Section titled “Solar System”
Data Source License
Planetary orbits and ephemerides JPL Horizons Public domain
Planet and moon imagery NASA / USGS Public domain
Mars atmosphere (Viking CO₂ cycle) NASA measured data Public domain

Beyond

Section titled “Beyond”
Data Source License
Exoplanet catalog NASA Exoplanet Archive Public domain
Star catalog (night sky) Hipparcos / public catalogs Public domain
Galaxy imagery ESA/Hubble, ESA/Webb CC BY 4.0 (credit required)
Cosmic web (18,000 galaxies) SDSS DR17 (Abdurro’uf et al. 2022) Public, cited
Black hole images Event Horizon Telescope CC BY 4.0 (credit required)

The licensing rule

Section titled “The licensing rule”

Only clearly usable, creditable sources ship. Public-domain (NASA, USGS, NOAA) needs no permission; CC BY 4.0 (ESA/Hubble, ESA/Webb, EHT) requires keeping the exact credit line. Non-commercial (NC), no-derivatives (ND), and unclear licenses are rejected. See Add a data layer honestly for the full workflow, and The honesty mandate for why.