Gradient practice

In this piece, I used the Add noise Filter and create the stars of the space, then I rendered the Clouds to create the nebulae and the Lens flare for the sun.
The planets are made using the Gradient tool, blur it and then adjust the blending options. Then create a highlight layer for each.
I think it will look better if I used some texture and lighting for the planets. But actually I dunno how to do that, hehe.