Distance Color Banding?

I have a large planet in my game, and from far away, it has a lot of odd circular color banding. My scene consists of a sphere, a fog post process material, and a scattering effect on the planet. The banding appears regardless if I turn off my post process material. Also, the sphere is beyond the distance dynamic light cascades, so it is not that. When I visualize scene depth, the rings produced by that match up to what I’m seeing on the sphere. Any ideas?