Getting Further from the Sun: How do you Ride an Epicycle?
I got the distance to Venus from a quick-hit measurement. For the superior planets, I was not saved from arduous labor by quick wit. I had to collect a lot of data and crunch many numbers. For both Saturn and Mars I collected more data than I absolutely needed. One reason for this was that I simultaneously read around to see if I could find a useable analysis technique. I simply did not know how much data I was going to need.
The other reason was that astronomy is my hobby, and I was simply having a bit of fun watching the apparent movement of the planets. I did not need to care very much about whether my science was efficient, unlike in the day job.
First, I will take you through my photographic techniques. I am not afraid to experiment, knowing that some ideas will bomb out – but I do keep things simple and stupid. Then I will show you how to extract the coordinates of a planet from a photo. My simplified model of the planet's orbit is that it is circular, so I will take you through...