I actually never tried something like this, but did some experimentation. Nothing special came out, but at least some sort of halo. But I didn't manage to have it light up on one side of the planet/moon, like in reality. Someone else may have a brilliant idea, but here's my 2 cents.
You did have your fractal warp wrongly attached; it needs the first input to work, and some fractal as input. So I added a simple terrain again.