In our solar system, we have 8 planets, and one dwarf planet, Pluto. Of those 8 planets, 4 of them are considered “giant” planets, and these are the ones with rings. We actually don’t know exactly why these planets have rings yet, but there are some hypotheses! Saturn’s rings are thought to be an accumulation of icy dust over billions of years. Jupiter’s rings are thought to be made up of particles that were blasted into space from micrometeorite impact’s with its moons. Therefore, Jupiter’s ring particles are constantly replenished.

As for Uranus and Neptune, their rings are still a huge mystery. They’re made of material much darker than Jupiter’s or Saturn’s. And planets aren’t the only celestial bodies with rings! Asteroids and moons can have rings too.

Big planets have more gravity and so attract more moons. Those moons that get too close to their planets or that collide with each-other break up, and those broken-up moons form the rinks of the planet.

You’re asking a really good question here, because this is one of the times scientists get to say “we don’t know”. One good guess is that they can only form around gas giants because in our solar system, that’s where the rings are. This might not be true though because some moons (which are more similar to Earth than they are to the gas giants) also have rings. Another thought is that they can only form around really cold plants. This makes sense for our solar system since the only plants with rings are really far from the sun. All of these thoughts are just hypotheses since we really don’t know yet. Maybe one day you’ll be the scientist that figures it out. Thank you for the question!