Saturn is one of the most fascinating heavenly bodies. It is unique because of its rings. It will interest you to know that the ring particles are made almost entirely of water ice, with some contamination from dust and other chemicals.
Get a nice background of black going.
With the airbrush tool, do the outline of Saturn and its ring. I've used transparent colours here. The airbrush can give the nice rotation effect to Saturn.
Add some colour to give a little life to the picture. There you are the Saturn in all its glory.