Looking good! Planets are well made and the starfield works. The only thing is that your planets need an atmosphere. There are some ways to do this, one is described in my tutorial, and a better way is described in Greg Martin's tutorial. I suggest you don't follow the technique he uses to build the planet itself in that tutorial (he doesn't use it himself), since it's a very simple technique and you can only end up with one result (except colors). But check out the atmosphere part in his tutorial. It's an easy and quick way of doing it.
http://gallery.artofgregmartin.com/tuts_ar...g_a_planet.html