Orbit Lines

Does anyone have any ideas on how I can make better orbit lines?

Currently, I am using planes with each planet that get re-scaled and relocated. Those planes have a material that makes them look like a ring. I am having several problems with this approach:

-The material has to be emissive to be easily visible. This lights up the sides of the planets and anything else nearby to the lines.

-They are not all uniform size. The ones near the sun are thin and they get ticker as the distance from the sun increases.

-They are not centered on the planets and because the scale is multiplicative, there will always be some that are not centered when I try to adjust it.

-They often appear broken apart, especially ones that are further away.

Here is a screenshot demonstrating most of these issues:

Is it possible to simulate a circle in 3d space with a widget?