How do the inner moons of Jupiter ( Ganymede,Europa, and Io) maintain their 1:2:4 orbital resonance?

If the orrery accurately represents the moon's orbital periods, it'll show that for every orbit Ganymede completes, Europa completes two and Io will complete four, displaying the Laplace resonance.

PROCEDURE -

1. We created an orrery to demonstrate the resonance among three of Jupiter's Galilean moons.
2. A metal rod was placed in the middle of the baseboard to hold these celestial bodies.
3. Every celestial object represented in this model was painted carefully so that it would slightly represent its inspiration
4. Each orbit arm, using a popsicle stick, was placed so that it would rotate Jupiter from its correct distance.
5. Jupiter was positioned so that it would stay at the centre and the top of the rod.
6. The rod's security came from its being glued down
7. Each arm was organized in a way that it would follow the 1:2:4 ratio between the moons.
8. To test the project, all that was done was to make sure each arm could spin around Jupiter.
9. Many adjustments were made to improve balance and accuracy.

MATERIALS -

• Popsicle sticks
• Acrylic paint
• Tape
• Wooden baseboard
• Styrofoam Ball
• Wooden balls
• Metal stick
• Glue

VARIABLES -

Manipulated: The manipulated variable in this case is the number of rotations each arm does.

Responding: The responding variable in this case is the number of orbits each moon completes around Jupiter.

Controlled: The controlled variables in this case are the model itself, the things that were used, the direction and method used for each rotation, and the distances between Jupiter and the moons.

The repeating pattern which was observed in the orrery is a well known example of orbital resonance, this is when orbiting bodies will influence each other using gravity. Jupiter has a strong gravitational pull which plays a big role in things, however the moons can also affect one another slightly while passing by. These gravitational tugs keep the moon locked into the 4:2:1 gravitational orbital ratio described before.

Orbital resonance also keeps the system stable by preventing the moons from colliding or drifting into unpredictable paths. Instead of being pulled out of the orrery the moons will instead be settled into one balanced rhythm. This same sort of resonance can be found in many parts of our solar system, such as Saturn's moons.

The orrery demonstrates that Jupiter’s strong gravity causes orbital resonance by synchronizing the motion of nearby bodies. The repeating orbital ratios confirm that gravitational interactions shape the structure of planetary systems.

Wikipedia. (n.d.). Orbital resonance. In Wikipedia. Retrieved February 4, 2026, from https://en.wikipedia.org/wiki/Orbital_resonance The Planetary Society. (n.d.). Orbital resonances of Galilean moons. Retrieved February 4, 2026, from https://www.planetary.org/space-images/orbital-resonances-of-galilean-moons [Channel Name]. (2026, January 5). Jupiter’s Galilean moons: Orbital resonance [Video]. YouTube. https://www.youtube.com/watch?v=HcKg-Rf0QVc Wikiversity. (n.d.). Galilean moons of Jupiter. Wikiversity. Retrieved February 4, 2026, from https://en.wikiversity.org/wiki/Astronomy_college_course/Galilean_moons_of_Jupiter#:~:text=The%20three%20inner%20Galilean%20moons,orbit%20via%20their%20gravitational%20interactions. Wikipedia article on Jupiter Wikipedia contributors. (n.d.). Jupiter. In Wikipedia, The Free Encyclopedia. Retrieved February 5, 2026, from https://en.wikipedia.org/wiki/Jupite . Nature article “Galileo at Jupiter — Meetings with remarkable moons” McKinnon, W. B. (1997). Galileo at Jupiter — Meetings with remarkable moons. Nature, 390(6655), 23–26. https://doi.org/10.1038/36222 DATA TABLE - FROM GOOGLE CHATGPT - HELPED WITH MODEL, IDEAS, BRAINSTORMING TOPIC, AND PARAGRAPH STUFF (nothing copied though) The Worlds of David Darling. (n.d.). The inner three large Galilean moons of Jupiter — Io, Europa, and Ganymede — are locked in orbital resonance [Facebook post]. Facebook. https://www.facebook.com/TheWorldsofDavidDarling/posts/the-inner-three-large-galilean-moons-of-jupiter-io-europa-and-ganymede-are-locke/1285446266717592/

We would like to give thanks to each other for working so hard together on this entire thing, Ayo’s parents as they did purchase all the materials that we used to build this, Ms. Lai for presenting this opportunity for us. We would also like to acknowledge being on the land of the treaty 7 which includes the Blackfoot Confederacy, Tsuu’T’ina, and the Stoney Nakoda Nations, and the judges who took time out of their day to come and judge our project.