Meridian texture sources. All files are NASA imagery in the public domain,
downloaded directly from NASA and resized for the web.
Fetched 2026-09-28.

Earth surface (Blue Marble)
  File:    https://eoimages.gsfc.nasa.gov/images/imagerecords/57000/57730/land_ocean_ice_8192.png
  Dataset: https://visibleearth.nasa.gov/images/57730

City lights (Black Marble 2016)
  File:    https://eoimages.gsfc.nasa.gov/images/imagerecords/144000/144898/BlackMarble_2016_3km.jpg
  Dataset: https://visibleearth.nasa.gov/images/144898

Clouds (Blue Marble)
  File:    https://eoimages.gsfc.nasa.gov/images/imagerecords/57000/57747/cloud_combined_8192.tif
  Dataset: https://visibleearth.nasa.gov/images/57747

Topography (Blue Marble)
  File:    https://eoimages.gsfc.nasa.gov/images/imagerecords/73000/73934/gebco_08_rev_elev_21600x10800.png
  Dataset: https://visibleearth.nasa.gov/images/73934

Moon surface color (LRO LROC WAC)
  File:    https://svs.gsfc.nasa.gov/vis/a000000/a004700/a004720/lroc_color_16bit_srgb_8k.tif
  Dataset: https://svs.gsfc.nasa.gov/4720/

Moon elevation (LRO LOLA)
  File:    https://svs.gsfc.nasa.gov/vis/a000000/a004700/a004720/ldem_16.tif
  Dataset: https://svs.gsfc.nasa.gov/4720/