Many of you may have wondered the reason why Saturn has rings. Why does this planet have such glorious rings while the other planets don’t? What are the rings made of? Let’s find out in this article.
To clarify things, a ring surrounding a planet is not a solid ring. Instead, it is a ring-shaped collection of small particles and rocks that orbit a planet together. It is mostly made of ice, dust, and rock, just like what an average asteroid looks like.
Also, Saturn is not the only planet with rings in the Solar System. All four outer giant planets, Jupiter, Saturn, Uranus, and Neptune, have rings. It’s just that Saturn’s rings are so apparent that they are easily seen in an image of the planet.
The Formation of a Ring
How does a planetary ring form? It forms from an object that breaks up under gravitational forces. Imagine that a large natural satellite is now getting close to a planet. The side closer to the planet receives a stronger gravitational pull than the side farther from it, creating force asymmetry and essentially tearing the satellite apart.
Usually, the force is countered by the satellite’s gravity holding all its materials together. However, if the force is too strong, the satellite starts breaking up. At that point, the satellite crosses the Roche limit, where an object is torn apart due to tidal forces.
At this point, the matter gets scattered around the planet as the orbits of the rocks continue shrinking. Some rocks fall faster than others, so they complete an orbit faster than their peers. A ring-shaped structure starts forming as the pieces get farther and farther away from each other and, eventually, around the planet.
On the other hand, there is also one way that a ring could form without a satellite getting to the Roche limit. In that case, one of the satellites orbiting Saturn may have crashed into an asteroid at such a high speed that small pieces of rocks get ejected from the satellite and the asteroid. The impact forces scatter the fragments around in slightly different orbits, meaning that some orbit faster and some orbit slower. Again, this means the formation of a ring-like structure around the planet.
Why Don’t Other Planets Have Apparent Rings Like Saturn?
At this point, you may ask, “Why don’t other planets have such rings while Saturn has one”? As it turns out, this effect can happen for any planet. Whenever a satellite reaches its Roche limit, it breaks down and forms a ring. However, most of them are not large enough for the rocks to become dense enough for a ring to become clearly visible. It might just be a coincidence that Saturn has magnificent rings, whereas other planets do not.
However, as the rocks fall towards the planet, the ring will get closer and closer to the planet and ultimately be absorbed by it. This will lead to the disappearance of Saturn’s rings within a few hundred million years.
In this article, we’ve mentioned why Saturn has rings. More specifically, it’s the process of forming rings that is the most important, and Saturn might just be lucky to have a giant ring system forming at the right time for humans to be able to see it. If you would like more information regarding this, please visit the webpages in the references below. Also, if we missed any crucial hypotheses about how a planetary ring forms, please leave that in the comments section so that we can improve our article.
- (2021, August 18). Saturn. Retrieved July 4, 2022, from https://solarsystem.nasa.gov/planets/saturn/in-depth/
- (n.d.). Why does Saturn have rings? Retrieved July 4, 2022, from https://www.planetsforkids.org/why-does-saturn-have-rings.html
- (2018, December 17). NASA Research Reveals Saturn is Losing Its Rings at “Worst-Case-Scenario” Rate. Retrieved July 4, 2022, from https://solarsystem.nasa.gov/news/794/nasa-research-reveals-saturn-is-losing-its-rings-at-worst-case-scenario-rate/
- Jerry Coffey. (2011, February 15). Why Does Saturn Have Rings. Retrieved July 4, 2022, from https://www.universetoday.com/84129/why-does-saturn-have-rings/