I was thinking of making a simple 2D model of the solar system, with planets moving along ellipses like
$$x(t) = k_x \sin(t + k_t) (\sin(k_\phi) + \cos(k_\phi))$$
$$y(t) = k_y \cos(t + k_t) (cos(k_\phi) - \sin(k_\phi))$$
and, for earth at least, a angle that some longitude (say the Greenwich Meridian) is facing in the $xy$ plane:
$$d(t) = k_dt+k_e$$
or something equally minimal.
Two questions:
- Where can I find the appropriate constants in the most cut-and-paste-able form?
- How long will this kind of model be accurate for? (If I want to use it to vaguely look in the right part of the sky for a particular planet)