Introduction
In Oct-2026,
a discussion on Reddit
spurred me to think about what it would mean for a planet to have an
Analemma.
I shared my thoughts on 20-Oct-2026. The relevant portion of that response is reproduced verbatim below.
...
For a planetary analemma (if one can call it that), things are a little complicated. You need to capture the
direction vector to the planet at a period that equals the mean duration between two successive transits across
the meridian by the planet. ...
For the outer planets (Mars onwards), to a first approximation, you can imagine that the planet is going around
the Earth in an approximately elliptical orbit. This would give you a very similar analemma curve as the Sun or
Moon -
except that it will only be a piece of the curve and will not be a closed loop as the planet will NOT
return to its original position at the end of a year. Further, there will be a retrograde loop superimposed on this main curve. How this would look like would
depend on the relative positions of the planet and the Earth in their orbits.
(The inner planets are going to be even more complicated.)
But, in theory, you could take a tool like Stellarium and take screenshots periodically (i.e., at a period that
matches the mean duration between two successive meridian transits for the planet you're interested in). Then
overlay all those screenshots on top of each other so that the meridian is aligned in all the shots. ...
...
I eventually followed up on my thought process above by taking screenshots on Stellarium periodically (at $7\times$
the mean meridian transit period for Jupiter) covering a span of $12$ years as that subsumes Jupiter's orbital
period of $11.86$ years. The screenshot sequence was then converted into a movie.
I shared the movie on 22-Oct-2026.
The rest of this post details the mechanics of how I did it.