Four the planets in the Solar System have rings. They are the four giant gas planets Jupiter, Saturn, Uranus, and Neptune. Saturn, which has by far the largest ring system, was known to have rings for a long time. It was not until the 1970s that rings were discovered around the other gas planets. The rings around Jupiter, Uranus, and Neptune are much smaller, darker, and fainter than the rings of Saturn. Rings around gas giants are thought to be transient over the the lifetime of the planetary system. That is, if we had lived at a very different time, perhaps we would not see big rings around Saturn, but another one of the gas giants.
