I asked this previously for my Earth project but it was never given an answer and was marked as a dupe which it wasn't as the question it was linked to was about textures being controlled by light, not the emission of an object. The effect would be somewhat the same however it shouldn't affect visibility but emission so that the objects emission fades when going dark.
For the atmosphere I'm using 2 spheres. One to act as the atmospheric distance you see where it gets more hazed the further away you look, and another which is the glow itself. For the glow I've found it works best with a volumetric material and have it emit light. The question I would like answered is, how would I control the emission of the volume material with the sun lamp in the scene? I have a strong feeling that nodes can make this happen but I have no clue on what ones would work.
I am working in Blender Render as I haven't figured out a better way to make a good looking Earth in Cycles yet.