Assume for a moment that there is a tenth planet. Also assume that it is about the same mass as Saturn.

1. How far from the Sun would it have to be for it to have no discernible effect on the known planets?
2. How long would it take to make one complete orbit?

I'm asking these questions as I'm working on an add-on for Celestia, a free space simulation and I'm no good at maths.
Thanks in advance.

1. There is no precise distance. It would also depend on the sensivity of the detection method.
2. That would depend on the distance.


best regards,

Dana