This has been a somewhat slow and extended personal project. Started out as wanting to make procedural planets, but once I made the ones I set out to make, I also wanted to turn everything into a solar system. Pretty happy with how everything came together.
Huge thanks to Alexey Lugovoy (here on ArtStation) for the moon shader. Took a while to "reverse-engineer" it, understanding it and making it work properly on current Blender.
Similarly, huge thanks to mrxstudios (on reddit) for the awesome gas planet shader. Took this one a bit further. It may be a bit less correct and more over-the-top, but I love how it came out.
Besides them, it was a lot of watching what others (a few of CBailey's videos on YT) do with planet shaders, understanding their node setups and experimenting myself.
Adalon - desolate world (animation) (CYCLES)
Arokh - gas world (animation)