This is a Terragen 2 render. Original size : 1152 x 864. Terrain and materials are pure procedural. Four layers of clouds : high level cirrus, mid level low density cumulus, mid level high density cumulus, and low level volumetric fog. I spent a lot of time looking for the best point of view on this one. A mix of realism and scifi mood was the challenge.
I hope you will like it. Thanks for comments / critics.