The very first interactive element is a great example of why ciechanow.ski is so great. Similar animations from other sources would probably limit to 28 frames and fake the image (using a simple mask). On ciechanow.ski there are hundreds(?) of frames and uses a bump map(?) to show accurate crater shadows on the moon's surface.
It goes way further than simple bump mapping. In terms of texture, there is a color texture and a height map, and the final rendering use real-time physically based rendering (PBR) techniques that takes into account the properties of the lunar regolith, as explained near the end of the article.
Color space is taken proper care of, and for images as rendered from the Earth point of view, there is a model of the atmosphere, so that the sky looks blue during the day and the Moon looks red at the horizon.
There are no pre-calculated images and only 3 photos. All the shading is done in real time using realistic models.
