I have to say that I really dig the render at the bottom. The colors and detail are fabulous, and the clouds look fantastic, a lovely contrast to the flat stratus clouds you usually see in Terragen renders. You used a good degree of color variation while keeping the overall cold, distant color scheme intact, and it looks great.
However, the planet above it detracts from that a little. The green of the continents contrasts sharply with the purple clouds, and that kind of sucks because they look awesome individually but not so much together. Then you have the purple flare at the top of the planet matching the render below, but the green planet in between. I'd recommend taking the green out and replacing it with some purple, even if it wouldn't look so much like a habitable planet then. I think it'd make the image as a whole a lot more cohesive, though, and the color use there is the only thing that stops this from being fantastic.