cs3, apo 2.08 3d, and 6 (?) hours.
edit #1-added light to the rings, and more detail to the close planet/moon thing.
edit #2-changed gas planet texture to make it match up with rings, and changed their positions a tad. also changed size and position of close moon at the bottom. the most obvious change, the nebula. ive had this one for a while, but wasnt sure about it fitting this pic. needless to say, i tried it, and liked it enough to replace the nasa neb pic.
edit #3- ring lightness and position again.