Great use of colour and very good distribution, gives it good depth! 

nice painting. love the colors. simple but deep in detail.

yess. thats really great man.

I could not leave it alone.  I had to go back and add some shading to the asteroid and large planet the next day.  Not perfect, I would have liked to have shaded the big planet at a different angle, but due to the highlighting had to do this.  Anyway I think its an improvement.  I don't think the college students getting this will even notice.  LOL