Earth, Moon and Milky Way textures — real imagery, resampled for the shaders

moon_color.jpg
    NASA's Scientific Visualization Studio, CGI Moon Kit (LRO LROC WAC colour mosaic, LOLA elevation).
    https://svs.gsfc.nasa.gov/4720/
earth_day.jpg
    NASA Earth Observatory, Blue Marble: Next Generation with topography and bathymetry (June 2004),
    Reto Stöckli. https://science.nasa.gov/earth/earth-observatory/blue-marble-next-generation/
earth_lights.jpg
    NASA Earth Observatory, Black Marble 2016 (Suomi NPP VIIRS), Joshua Stevens / Miguel Román.
    https://science.nasa.gov/earth/earth-observatory/earth-at-night/maps
earth_height.jpg
    NASA Earth Observatory / GEBCO_08 grid (British Oceanographic Data Centre), Jesse Allen.
earth_clouds.jpg
    NASA Goddard Space Flight Center, Blue Marble: Clouds, Reto Stöckli / Robert Simmon.
    https://visibleearth.nasa.gov/images/57747/blue-marble-clouds
milky_way.jpg
    ESO/S. Brunier — The Milky Way panorama (eso0932a), licensed CC BY 4.0.
    https://www.eso.org/public/images/eso0932a/
