Last year I had some time to fill, and discovered that modeling planetary orbits with polar equations isn't too hard. If you can find the semi-major axis and eccentricity value of a planet or dwarf planet or comet or whatever, you can model its orbit. Naturally, I chronicled the results.

Rarely do I like the first result from a project.


  • not enough work, students twiddled thumbs
  • not enough devices to go around
  • my write up tried to do too much, as always
  • no connection to prior content
  • no discussion post project
  • no attempt to assess their understanding of what they made

At the time, I was looking for something unique to do, and this project did the job nicely. However, unless you were the student typing all the equations, you may not have gotten the math takeaways I wanted. Plenty of kids ooh'd and aah'd about science stuff throughout, but it was the "do you realize that we're modeling PLANETS? Like, big giants PLANETS?" that didn't work. I also made a request for them to define "eccentricity." Hint: never asks students to define stuff without guidelines. The result is some bullcrap from the first Google hit on their phone.


  • made the project scale, groups would have to model the Jupiter and Saturn systems if they had a large enough group
  • had more devices to go around, time could be spent finding resources for planet cards while others found equation info
  • scrapped the instructions and made it a landing page for researched information and a checklist of final products
  • integrated within the flow of polar equations
  • discussed planets and their behavior extensively prior to starting
  • held a post project discussion about what was observed
  • used the project to segue to polar equations of conics in general
  • included questions about the project on an assessment


The products turned out better. A field trip sort of sabotaged one class (students 1 & 2 missed day 1 so 3 & 4 started it, 1 & 2 then return to find 3 & 4 absent and have no clue what's going on), but it worked. After an initial 20-30 minutes of growing pains, everyone understood what was required.


Good discussions in the post game. On purpose I included some things they weren't used to: aforementioned Jupiter/Saturn moon systems, Halley's Comet, and the dwarf planet Eris. Every class had a rousing discussion about the fate of Pluto, when Halley's Comet will return ("man I'm probably gonna be dead"), and how an object could wind up with such a wobble.

I have versions of the intended graphs saved.

Solar System, Jupiter, Saturn


Fewer students were idle, more got an understanding of what we were doing, and all of them picked up at least something about space. Now, the math takeaway did not improve as much as I wanted, BUT with the project now an integral part of my trek through polar, that part would be solved in Part Two.

AuthorJonathan Claydon