My image (thread 34) actually has exactly the result I was looking for. The aura is very thin and very minor and is actually barely perceivable (This effect is more artistic than real so I wanted it to be very minor). My example is showing how it can be done pretty easily. You can change the magnitude or the color to get the level of desired effect (be it realistic or artistic or cartoonish or whatever). The glow will only appear on the lighted side of the planet and falloff to zero at the shadow line with a perfect gradient with respect to the light source. This should satisfy the question that was originally posted. The back of the planet will not be lit at all. -Kix

-Kix