I know that the bottom fog isn't that good but I only noticed it after rendering the image for an hour and didn't feel like wasting another hour when I was pleased with how the mountains and atmosphere came out.
I was going for an early morning scene in a frozen mountainous landscape. I added some stars at the very top to show how it just became daytime but not sure how well you can see them.
Terrain made in Terragen 2, everything else in CS5, and planet texture from NASA [link]
Hope you like it.