And every half hour, these images are composited and mapped onto a sphere by xplanet according to the relative position of the sun. The flat maps are post-processed by ImageMagick to cut off the 15 degrees nearest the north and south poles where cloud data is unavailable.
4 different types of maps: Mercator, Peters, Mollweide, Equirectangular
Dawn to dusk
Read more about how the maps are created here: World Sunlight Map: How it works
Open up the terminal Application > Accessories > Terminal and type following command
$ sudo add-apt-repository ppa:realtime.sunlight.wallpaper/rswLaunch from: Applications > Accessories > Real-time Sunlight Wallpaper
$ sudo apt-get update
$ sudo apt-get install gtk-sunlight