I have been playing around with different pieces of 3D software, trying to make space scenes (here's an image made with Carrara). This image was made with DAZ Studio, because I wanted to see how well DAZ Studio worked for this kind of image.
The answer seems to be ‘reasonably well’. The planetoid in the foreground is a simple sphere, textured using a rocky ground texture and then wrapped in a second sphere to which a cloud texture has been applied. The result was a little dull on its own, so I added some buildings to the surface. Add a cloudscape as a backdrop, and some starships to balance the composition, and there you have it.