The rings of Saturn are the most extensive planetary ring system of any planet in the Solar System. These rings consist of small particles anging in size from micrometres to metres which orbit around Saturn. The ring particles are made almost entirely out of water ice, with a trace component of rocky material. There is still no consensus as to their mechanism of formation; some features suggest a relatively recent origin, but other theoretical models indicate they are likely to have formed early in the Solar System's history.
Although reflection from the rings increases Saturn's brightness, they cannot be seen from Earth without aided vision. In 1610, the year after famous astronomer Galileo Galilei first turned a telescope to the sky, he became the first person to see these rings, although 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.