There are four planets that have rings. Before reading on, try to guess which planets have rings. Any luck? Alright…Jupiter, Saturn, Uranus, and Neptune all have ring systems. Of course, the rings of Saturn are the most spectacular, first known, and most recognizable.
The rings of Jupiter were not discovered until 1979 when the Voyager 1 space probe flew by the planet. The Jovian ring system is faint and consists mainly of dust, it takes the largest telescopes to observe them. The ring system has four main components: a thick inner torus of particles known as the “halo ring”; a relatively bright, but extremely thin “main ring”; and two wide, thick, and faint outer “gossamer rings”. These outer rings are composed of material from the moons Amalthea and Thebe and are named after these moons.
Saturn has 12 rings and 2 divisions. It has the most extensive ring system of any planet in our solar system. These rings consist of countless small particles, ranging in size from micrometers to meters that form clumps orbiting the planet. The ring particles are made almost entirely of water ice that is contaminated with dust and chemicals. Saturn has several moons that are within the rings.
Uranus has 13 rings that have been observed so far. They are all very faint. The majority of Uranus’s rings are opaque and only a few kilometers wide. The ring system consists mostly of large bodies 0.2 to 20 m in diameter. A few rings are optically thin and are made of small dust particles. Sort of hard to pin these rings into an all encompassing label.
The rings of Neptune were not discovered until 1989 by the Voyager 2 space probe. There are six rings in the system. The system is faint and tenuous at best. There are four moons orbiting within the ring system. The rings are made of extremely dark organic material that has been irradiated.
Now that you know which planets have rings, what are you going to do with it? Use it as a trivia ice breaker at parties? That is what I would do, anyway.
We’ve also recorded a series of episodes of Astronomy Cast about every planet in the Solar System. Start here, Episode 49: Mercury.