How to distort background images?

I'm trying to put a cool blackhole effect into my game. I found an image of a black hole I would like to imitate. What do I need to do to accomplish this task?

I also have an additional side question. When player goes into blackhole, I would like to do an animation of a clock twisting from the center. I figured I would do this with a sprite animation, but does unity have a tool to accomplish this already?