This is good. I like the nebula a lot. Lighting is quite nice as well. I think that there might be a bit too much negative space though. Perhaps paint in some more stars or other things to fill up space?
the nebulae are fantastic! I find being pulled in by both sides. Great work. (I really am sorry that I always find something to critique about, I'm too picky, but I think the main planet doesn't fit exactly with the neutral theme. It sticks out on its own as what looks like an independent planet, instead of one under conflict. Maybe that was the point, but even so, the cloudy planet is to white it doesn't mesh into the painting as a whole) All that said, I am still going to put this on my desktop! It's pretty amazing seeing your huge jumps in skill and these nebulae really show your mastery!