Why do some planets have rings?

Saturn

We know many planets that have some kind of ring system. And the most well-known of those planets is Saturn. All gas giants in our solar system have a ring system that orbits them. So there are many theories about the origin of those rings. 

There is the possibility that forming of the rings is unique. So that means there are more than one reasons why some planets have rings. But if we are thinking about the gas giants in our solar system we must realize that those planets are more distant than Earth. 

So solar wind in that area is weaker than in the Earth's distance. And that means the particle (or ion) flow from the Sun would not blow those particles away. That explains why Earth has no rings. The reason for that is the solar winds. That are blowing sand or some other particles away from the Earth's orbiter. 

"The backlit (of Saturn's) E ring, with Enceladus, silhouetted against it. The moon's south polar jets erupt brightly below it." (Wikipedia/Rings of Saturn)

There may be many things that are forming ring systems for planets. There are three of those theories. And maybe there are many other reasons why some planets have rings. And some have not. 

*Plasma- or Van Allen rings of the planets are capturing sand bites that travel at the solar system. 

*In the case of Saturn, the shepherd moons are also playing their role in forming and anchoring the ring system. The shepherd moons are moons. That is orbiting the ring system on both sides of it. And the gravitational fields anchoring the objects in their places. 

*The Van Allen belts could capture small particles. And that explains why Uranus' rings seem to have no shepherd moons. The Van Allen ring or plasma ring can capture very light and slow-speed objects. So that means there could be many reasons why some planets have rings. 

*If the planet's distance is high enough from the Sun solar wind would not blow that dust away. 

*Destruction of the ancient moon can explain ring systems that involve large particles. 

*That moon could be destroyed by cosmic impact. Or tidal forces of the planet and its other moons can destroy that ancient moon. 

The planets with ring systems 

a) Jupiter's rings

a) "A schema of Jupiter's ring system showing the four main components. For simplicity, Metis and Adrastea are depicted as sharing their orbit. (In reality, Metis is very slightly closer to Jupiter.)" (Wikipedia, Rings of Jupiter) 

a2)

"Metis orbiting at the edge of Jupiter's main ring, as imaged by the New Horizons spacecraft in 2007" (Wikipedia/Rings of Jupiter)

b) Saturn's rings

"Side view of Saturn system, showing Enceladus in relation to the E Ring" (Wikipedia/Rings of Saturn)

b2)

"The full set of rings, imaged as Saturn eclipsed the Sun from the vantage of the Cassini orbiter, 1.2 million km distant, on 19 July 2013 (brightness is exaggerated). Earth appears as a dot at 4 o'clock, between the G and E rings." (Wikipedia/Rings of Saturn)

c) Uranus rings

"The scheme of Uranus's ring-moon system. Solid lines denote rings; dashed lines denote orbits of moons". (Wikipedia/Rings of Uranus)

"The scheme of Neptune's ring-moon system. Solid lines denote rings; dashed lines denote orbits of moons".

d) Neptune rings

d2) "Rings of Neptune imaged by the James Webb Space Telescope's NIRCam instrument" (Wikipedia/Rings of Neptune)

*There is the possibility that the planet capture the large dwarf planet and then the tidal forces will rip that dwarf planet in pieces. 

*In that case. The shepherd moons or moons that are orbiting the planet at both sides of the ring system are anchoring those objects in their places with their gravitational effects. 

And that means there is a possibility the plasma rings or Van Allen rings of giant planets capture dust, asteroids, and comets that travel in solar systems. And at least in cases where the ring system is formed of sand or other way saying small-size particles. That is the reason why some gas planets have rings. 

Another reason could be the ancient moon that is broken by cosmic impacts. That thing can be a reason, for planets like Saturn have larger objects in their rings. When that hypothetical moon is destroyed. The particles that are remaining of that ancient moon left to orbit Saturn. 

In some of this theory's other versions, Saturn collided with an asteroid cloud that could be the remnant of some ancient dwarf planet and some of those remnants remained to orbit that planet as the well-known ring system. 

https://scitechdaily.com/why-are-some-planets-surrounded-by-rings/amp/

https://en.wikipedia.org/wiki/Rings_of_Jupiter

https://en.wikipedia.org/wiki/Rings_of_Neptune

https://en.wikipedia.org/wiki/Rings_of_Saturn

https://en.wikipedia.org/wiki/Rings_of_Uranus

https://en.wikipedia.org/wiki/Tidal_force

By the way...

The idea of the solar ring- or ring-shaped solar panels is taken from the planetary rings and one hoax theory. 

There is one UFO theory that I want to mention here. That theory is that the Uranus ring system is the solar panels that are orbiting the gas planet. Today that theory is crushed, but it gave an idea that maybe in the future Earth and some other planets or space colonies will get their power from solar panels that orbit the planets. 

The energy will transport to those colonies in the form of radio- laser or microwaves. That kind of solar ring or extremely thin silicone panels might solve the energy problems of the future. If those solar rings or ring-shaped solar panels are rotating or orbiting the Earth or some other planet the gravitational and centripetal force would have the same power, and they would anchor that solar panel in place. But that thing requires that the panels will move all the time. 

It's possible that between the center planet and the inner edge of the silicone panels is the frame. The orbiting silicone panel delivers energy to that stable frame. And that frame sends energy to the receiving stations on Earth. 

Image: Pinterest