I've been looking at this on and off for a few hours, and still feel it's definitely missing something, but I'm not entirely sure what, yet, either.

Part of the ship carrying the camera on the edge of the view somewhere, perhaps? Or another ship in the view?

I think the problem might lie in that gap between the nebula and the top left corner-thingy around the planet, but I'm not wholly sure.


...
Actually, I take that back. I just looked at it again, and I think the amount of stuff is just right. Try bringing the opacity of the grid down as low as you can without losing sight of it. Basically to the point where it's still clearly visible, but that your eyes are drawn first to the planets.

Space is often empty; highlight that. Silence can be music and emptiness can be art, too.

-asp