To make the orbit of Jupiter visible against the background stars I used 18 images taken over the last few months.
Visualizing the orbit:
Step 1: Rotated each image until the orbit of the Galilean Moons was horizontal.
Step 2: Aligned the images on Iota Capricornus, a star visible on all images.
On October 13, 2009 the more or less linear orbit of Jupiter changed into the opposite direction. I had captured the end of the 2009 retrograde loop of Jupiter!
Retrograde loop explained:
Location: Tilburg, Netherlands
Date: September 7, 2009 - November 15, 2009