He did ask for advanced Critique, so here it is.

I dont like it much, the planet is way too huge. it also doesnt help that most of it is covered in black, kind of leaves it empty. i do like the stars and the space dust, looks very well done, but maybe try and mix it up a little, mix up the colours. also, the texture used on the planet isnt that good, try a different one next time. also, add a light source, makes it look like your actually in space, and its not just a picture.