Teslarati's SpaceX just expanded the envelope of rocket recovery with 50th booster landing includes some beautiful examples of Richard Angle's work portraying time and motion and physical processes. The sequence of launch, stage separation, boost-back and landing is many minutes, and this results in star trails.
Question: Why are the star trails so non-uniform? Why is each star trail non-uniform along its length and why does every trail show the same pattern of brightness variation along its length?
Falcon 9’s MECO (the gap) and boostback burn (backwards curly-cue). The lefthand arc is the rocket’s upper stage and Cargo Dragon payload continuing on its way to orbit. (Richard Angle)