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Which planets have a ring-system?

Of the nine planets in the Solar System, four of them have rings around them. The four planets

that have rings are the gas giants, Jupiter and Saturn, and the other two gas planets, Uranus and

Neptune.

Saturn has always been known for its ring system of vast and spectacular rings. The rings are

about the same age as the human race (3 million years) and are easily visible through a telescope

or high powered binoculars (chose a year when they are not directly side on).

The visible rings reach out to about 84,650 miles (136,200 kilometers) from Saturn’s

center. Saturn’s rings are composed of bits of debris that range in size from pebbles to

boulders and are a mixture of water ice and dust. The rings in some places are only 16.4 feet (5

meters) thick. It is the ice in the rings that makes them so bright and they are broken up into

thousands of little rings or ‘ringlets’ by the gravitational pull of the planet.



In August 1981 four years after it launch in 1977 the Voyager 2 space craft passed Saturn but

sent up back some great pictures of its rings. Voyager 2 counted over 100,000 thin rings in the

Saturnian system. Saturn has well earned its nickname of ‘Lord of the Rings’!

The Voyager space craft flew by Jupiter in 1979 two years after it launch and discovered a faint

system of rings consisting of the outer ring known as the “gossamer” ring and the

main ring. The rings are made from debris caused by impacts of cosmic material on the inner

moons. The rings of Jupiter are moving inwards towards the planet and therefor need material to

keep them ‘alive’.
The gossamer ring is made up of inner and outer rings orbiting separately. In 1988 the Galileo

space craft flew through the Jovian system of moons and scientists found that the main ring is

made up of material from the moons Metis and Adrastea while Amalthea and Thebe make up the

material for the gossamer rings. The halo is made from dust pulled from Jupiter’s outer

rings by the planet’s electromagnetic field.

In 1977 five rings were discovered around Uranus. They are 31,860 miles (51,300 kilometers) from

the center of Uranus and are 5,840 miles (9,400 kilometers) wide. Four more were discovered in

1986 during the fly by of Voyager 2 and more have been discovered since.

Neptune has five thin rings around it but these were not discovered until 1989 when Voyager 2

past the last stop in our Solar System of the Grand Tour. It was thought in 1984 that Neptune had

rings after a star being observed winked out before the planet eclipsed it. Neptune’s two

narrow rings orbit at distances of 33,000 and 39,000 miles (53,000 and 63,000 kilometers) from

Neptune’s center.

I have made several batches of questions. This question is from the second batch. To find

other batches of questions plus the newest one return to the main h2g2 as Q and A page using the

first link below. Other questions in this batch are also below.

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If you would like to contact me please use this link:
Richard Derek Young.