At long long last I have got a grip of atmospheric scattering. Decades implementation of atmospheric scattering is based on Sean O'Neill's amazing research. In the video below you can see the sun rising in the sky as the camera moves around the planet. The word planet is used with grace as the planet is simply a smooth sphere which was procedurally generated with recursive subdivision. (See Post below). Close to the end of the video the rendering switches to wire frame and you can see the planet subdividing by another level.
As always there is a list of improvements to make. The planet is currently rendered in software, each face rendered separately. There is also no culling. Adding hardware acceleration and efficient culling should greatly improve performance. The subdivided implementation of the sphere allows easy culling of vast numbers of faces with a few checks.
I am also going to look more detailed at realtime fractal terrain generation, possibly with Perlin Noise so as I dubdivide the planet as the camera gets closer the result will be a details, rich looking terrain.