Very nice! I like it pretty much. The big planet looks good.
But I think the lighting for the big planet is a tad off since the light is in that position. The cresent would probably be thinner. Also, IMO you could have a little less clouds, so there're more dark areas.
The sun is very well done, good job on that.
The text could be totally white and you could remove that shiny thing on the text, could probably be better without it.

Good job on this, you are definately one of the best here on the void when it comes to space art!