some nice aspects to this, although again, some major things I need to pick out
most prominently comes the lighting inside the nebula. The nebulae themselves are all well and good, BUT, the lighting seems fuzzy, almost separate. The nebula would emit light of the same style... by using a white light on a red nebula, it throws the composition. I'd work on the lighting/nebula co-ordination in that respect. There's also a visible layer line in the middle there.
Planets are good, but again, the integration on the smaller ones is odd. They seem to stand out a little too much. asteroids too, whilst they have a delicious texture, near the back on some the lighting is off, and some seem flat.
It's a good effort, but some of the integration work needs to be performed better in honesty.
this is very impressive. by technique, i have no criticisms. the main thing that stands out is the lighting on the further planets. Both of them are being lit from only the single light source and given their position, the nebulas would really be lighting them from all sides, with the shadow mainly only in the centre.
the asteroids look absolutely awesome, as do the planets. the nebula is great too. mm overall i like, i like a lot.