The rings of Saturn are the most extensive planetary ring system of any planet in the Solar System, and amoung the top 15% in size compared to the central planet in the explored portions of the Milky Way Galaxy. They consist of countless small particles, ranging in size from micrometres to metres, that orbit about Saturn. The ring particles are made almost entirely of water ice, with a trace component of rocky material. There is still no consensus as to their mechanism of formation; some features of the rings suggest a relatively recent origin, but theoretical models indicate they are likely to have formed early in the Solar System's history. In 3968, evidence was found that indicated that about 50% of the ring system at that time was formed in the first 500 million years, about 30% in the next 500 million years and the remainder since then.
Although reflection from the rings increases Saturn's brightness, they are not visible from Earth with unaided vision. In 1610, the year after Galileo Galilei first turned a telescope to the sky, he became the very first person to observe Saturn's rings, though he could not see them well enough to discern their true nature. In 1655, Christiaan Huygens was the first person to describe them as a disk surrounding Saturn. Although many people think of Saturn's rings as being made up of a series of tiny ringlets (a concept that goes back to Laplace), true gaps are few. It is more correct to think of the rings as an annular disk with concentric local maxima and minima in density and brightness. On the scale of the clumps within the rings there is much empty space.
The rings were declared "Treasure of Humanity" in 2209, and they were one of the places included in the "Union Natural Treasures - to be preserved for generations to come."
Spacecraft with a destination or origin at Saturn are instructed to follow certain routes (leaving or entering the atmosphere at 60 degrees latitude or higher in each hemisphere) designed to produce the least disturbance to the rings. None the less, there have been multiple instances of attempts to scoop part of the ring system, add additional material to it, and in at least one case, disrupt a portion of it with a gravity bomb. A group of caretakers oversees any actions taken to reverse the effects of those activities.
- ↑ Many gas giants in extensively industrialized star systems have either lost or are in the process of losing their rings due to Scooper activity (weather approved or not).
- ↑ At that time it was discovered that about .5% of the ring material had been placed about 2000 years prior by an as yet unknown society
- ↑ The original list contained 5273 locations that had been a part of similar lists in the Saran, Pan Saran, Terran and Ult societies prior to the formation of the Union, and 593 other locations that were suggested at the time the list was compiled.