Well that's clearly not a standard planet in the background. I would say asteroids, but since the green glow is layered over it, I assume that means it's all part of the background and not close up near the station that we're looking at. If that glow is all part of a nebula, I'll have to cry foul, because there's no way you're going to see a nebula on top of any sort of object in space. The scale would be ridiculously wrong. That is either a tiny nebula hanging out in front a nearby destroyed planet (hint, there are no tiny nebulae), or that's a distant nebula in front of a rock the size of 100 solar systems. I'm assuming neither, and that what I'm taking as nebula is actually just some weird glowy pixie dust on top of a background cracked planet.