Video Explains Why Orbital Resonance Is a Thing In a Relatable Way

The three largest moons of Jupiter, Ganymede, Europa and Io have orbital periods that are whole number ratios with each other. Find out why.

The workings of the stars, the planets, and the moons are hard for most of us to grasp but here in this video YouTuber Steve Mould explains one particular concept related to space, orbital resonance, in a way that can finally be understood.

"Incredibly, the three largest moons of Jupiter, Ganymede, Europa, and Io have orbital periods that are whole number ratios with each other (1:2:4). The big gap in Saturn's rings is caused by a moon much further out that has an orbital period double that of the gap! We've even found exoplanet systems with these patterns. They're all the result of orbital resonance. This video explains how that mechanism works," Mould writes in his video description.

The video first illustrates how there is no orbital resonance when it comes to the ratios of planets circling the sun. It seems that orbital resonance is a concept that's exclusive to moon-related phenomena.


Mould then goes on to explain the concept by using an illustration that features the moon and a rock in Saturn's rings. We can tell Mould is up to date with popular culture as he designates this rock with a picture of famous actor/wrestler The Rock. But what's most impressive is how simply and clearly he explains orbital resonance using this example. Watch the video and see for yourselves.

Follow Us on


Stay ahead with the latest science, technology and innovation news, for free:

By subscribing, you agree to our Terms of Use and Privacy Policy. You may unsubscribe at any time.