The last section of my daily Jupiter Today podcasts is a summary of the position of Jupiter relative to the Earth and the Sun. One of the values I report is the daily change in velocity (in km/hour). What I've noticed after these few months is that the change in velocity itself is changing.

So I decided to finally look into this a little more.

Below are six plots. The x-axis in every case is the number of days past 2015-Mar-22. The y-axis is the value of the parameter in the units described below.

The 1st plot is the distance from Jupiter to Earth (in km) over the course of ten years, sampled every day.

The 2nd plot is the difference in distance over the course of that day.

The 3rd plot is the radial velocity between Jupiter and Earth (in km per day).

The 4th plot is the change in the change in that radial velocity.

The 5th plot is the radial acceleration between Jupiter and Earth (in km per day per day)

The 6th plot (the one I'm most interested in) is the change in that radial acceleration.

To put this into language, what this last plot is showing is that not only is the change in velocity changing, but that change is changing too!!!! Confused????? So am I.

I've been trying to figure out a way to describe what this would feel like in our ordinary life. The best I can come up with is that we're driving a car over bumps that are changing their shape over time. So the amplitude (and frequency????) of the bumping is changing as we drive over them.

Looking at the plot itself, what do the maxima and minima represent? My best guess is superior conjunction and opposition. But which is which ... and why? Why does this plot have a "sawtooth" shape and not a sine wave shape? I'm fairly certain that the smaller wiggles are caused by Jupiter's moons.

For sure I need to look at this closer and in as many perspectives as I can.

If any of you have any ideas on how to interpret these plots, please comment!