In message .com,
oriel36 writes
To Kurtan

The original Keplerian insight on orbital geometry and motion refered
the orbit of Mars as seen from the Earth against the background stars -
Kepler called the plotted trajectory 'Panis Quadragesimalis', a
representation that is nowhere to be found on the entire internet .

Looks as if the gerald kelleher program has been partially erased :-)
According to one of your own posts
http://www.newsfeeds.com/archive/sci-astro-amateur/msg27075.html it's
depicted at
http://culturesciencesphysique.ens-lyon.fr/Entree_par_medium/Animations/Mouvement_Mars
Well worth looking at,

Because the sidereal format attributes a
constant .986 degree orbital displacement

For about the thousandth time, it doesn't. That's a simplification used
in examples such as the one below to avoid complicating things with
elliptical orbits. Over a year, the average is 0.986 degrees,


unfortunately it generates the odd spectacle
of the Earth travelling faster at the aphelion and slower at the
perihelion -

http://www.pfm.howard.edu/astronomy/...S/AACHCIR0.JPG

As usual, this link has absolutely nothing to do with what he is
describing, which is a simple consequence of an elliptical orbit. Does
he grab them at random from a very small selection ?