Professional quality. This scene is really awesome... though, I don't really see the point in making that sort of thing, for someone as good as you, since it requires only a good control of photoshop, and not your talent.
But back then i was just started with photoshop and i was very interested in space art. Now that i do paintings, i dont do space art very often anymore.
I do make space scenes where i actually paint the whole thing including planet. I will submit one soon.
The stars and nebulae itself is great. The biggest planet is ditto, but it's shadow is 100% black. That's a bit queer, I suggest you lower the opactiy of it to 92/93% in order to make it a bit better. Also, I agree with atd, but if the light source is really far away, you're excused
The signature and the frame isn't the best I've seen. Try fixing that on your coming pieces, it deserves better.
OMG!!! I really REALLY love this image...now dern it, if only I can get my stuff to look like this!!! LoL (Look in my gallery and you'll se what I mean haha ) This is so going on my favs Wonderful, thanks for sharing!!! hehe
Looks awesome man. Really superb detail on the nebulae in the background. The planets overall are good, however the shadows need a bit of work. On my monitor you can see outlines of them Doesn't distract the eye from the overall detailing of the image though. Great job and wonderful idea