Oh right, how did I make it look like the nebula is inside the glass ball? I took the original image and used a magnetic lasso or circular selector to copy the ball to a new layer. After the effects with the actual nebula I (think I) overlayed the cut layer onto the image, and lowered the opacity. There's probably a circular overlayed gradient too to give it a 3D look.
I am so stupid
I do not know if I understand ...