Some info about model:

• Nodes with the textures are labeled to make it easier to understand where and what texture to add
• Clouds cast shadows on the ground
• Illumination of the night city appears only on the dark side of the Earth. And it doesn't matter what you'll rotate - Earth or light sourse. The drivers check the angle of rotation of the sun lamp and apply a texture based on this. So technically there is no check if the side is dark, but the mask for that texture rotates based on the angle of the light source. And it works
• If you already have the light sourse in your scene and wanna use it, you need to specify your light source as an object in the Driver settings in the Mapping node (Earth material)
• Works best with a Sun lamp. Of course, you can also use a Point lamp, but remember to rotate it the same angle that the planet rotates around the lamp
• There is an Empty in the center of the planet, it has the same rotation parameters as Earth. It is needed to correctly determine where the illumination should be
• Atmosphere, Clouds and Earth - 3 different objects
• 4608 faces & 4614 vert
• Texture pack from 2048x1024 to 21600x10800

If you have any questions or want to discuss smth write to me and I will reply as fast as i can