On Sun, Jan 21, 2018 at 05:25:13AM -0500, Caleuche wrote:
> A significant perturbation and enough so that you wouldn't use two
> body elements for anything other than a first order approximation.

You never would use two-body elements for anything but a first
approximation anyway.  The perturbation due to a planet like Jupiter
at 5 AU is on the order of 300 times greater than that station at
10 km.  It's only over the longer timescales (centuries and beyond)
where the perturbations from large gas giants usually cancel out.
They cannot be ignored in the medium term.

Using a simple Keplerian model to track asteroids in reality would
yield errors of up to a million kilometres after a decade, depending
upon the relation of the asteroid's orbit with Jupiter.  Ignoring the
other gas giants would result in lesser but still quite significant
errors.

- Tim