There's a tut that'll greatly help you with planets, spanning a few pages long and really in depth. I can't get the page right now, my internets being stupid.

When I find it, I'll tell you (hopefully by tonight).


But for a first, it's decent. I think there should be more negative space in the composition, because... quite frankly, the planets not really interesting, and the planets texture is a bit plain and repetitive (lines going across).

I'm sure rabies can touch up on more things like the background and stuff, I'm lost at words to guide you further, as if I had did that in the first place :P; I'm starting to learn space art myself so I can broaden my range of art styles

I think the bg should have more depth, as of now it looks flat.

GJ for a first, though! I'll look forward to your future pieces.