Timekeeping and retrogrades

The observed stationary points between observed motions of the inner and outer planets have two distinct causes -

http://astrobob.areavoices.com/files...el_bigANNO.jpg

The faster moving Earth approaching Mars in that image is much like a car in an inner lane approaching a slower moving car in an outer lane as the car falls temporarily behind in view as the faster care starts to overtake the planet and best seen in the images of Jupiter and Saturn -

http://apod.nasa.gov/apod/image/0112/JuSa2000_tezel.gif

The stationary points of the inner planets represent when those planets are furthest from the Sun from our slower moving Earth before those planets swing in front of the Sun and move from an evening appearance to a morning appearance -

https://www.youtube.com/watch?v=MdFrE7hWj0A


The same happens with the background stars as they disappear behind the glare of the stationary central Sun as the Earth moves through space and show up as a morning appearance a few months later. It is crucial to understand this observation insofar as the foundations of timekeeping rely on the observation that as Sirius shows up for the first time as a morning appearance, it skips an appearance by one day after four cycles of 365 days/rotations.

Putting the motion of the inner planets as they move from an twilight to a dawn appearance or from the left side to the right side of the Sun makes the line-of-sight appearance of the background stars as they disappear and reappear in sequence as proof of the Earth's orbital motion -

https://www.youtube.com/watch?v=eeQwYrfmvoQ


Building astronomical insights from scratch using imaging is even more exciting than building the first computers in garages and leaving behind those who simply can't keep up.