I think the planetary body is very well done, I also like the construction, the peices fit together nicely...I however think the stars could do with some more effort. It seems like you put hours into the picture but added the stars as an afterthought...
As a result it looks like the red nebula ...well it kinda sticks out a bit too much.
Keep 'em coming, I might try my hand at one of these sometime soon.
Heh. That nebula gave me so many problems. It's my first one. XD
As for the stars...well, I guess I just forgot about them. They were there since the start of the picture, and I guess I grew used to them. I was going to add something to do with them, but it slipped my mind.