I wrote a shader for rendering realistic earth with the most basic version of shader.
The lighting model is the most basic Phong shading model, the normal map is not that correct, the color of the light source is hard-coded in the shader. Everything is messy… But it looks good~! 
PR and Issues are welcomed!
Sources:
Textures: VIDEO COPILOT ORB plug-in
Blog by christian: Normal Mapping Without Precomputed Tangents