Elena Dang and Safiyyah Hossain

Saturn is the second largest planet in our solar system. Saturn has seven thin, flat rings around it. The rings are made up of ice particles that travel around the planet. Jupiter, Neptune, and Uranus also have rings, but their rings are much fainter than those around Saturn.

Saturn is the sixth closest planet to the sun. Its average distance from the sun is about 890,750,000 miles. At its closest approach to Earth, Saturn is about 742,800,000 miles away.

Saturn's diameter at its equator is about 74,900 miles almost 10 times that of Earth. The planet can be seen from Earth with the unaided eye, but its rings cannot. Saturn was the farthest planet from Earth that the ancient astronomers knew about. They named it for the Roman god of agriculture.

Saturn travels around the sun in an elliptical (oval-shaped) orbit. Its distance from the sun varies from about 941,070,000 miles at its farthest point to about 840,440,000 miles years to orbit the sun at its closest point. The planet takes about 29 1/2 Earth.

Saturn rotates faster than any other planet in our solar system except Jupiter. Saturn spins around once in only about 10 hours 33 minutes. The rapid rotation causes Saturn to bulge at its equator and to flatten at its poles. The diameter of saturn is 8,000 miles larger at the equator than it is at the poles.

As Saturn travels around the sun, it spins on its axis, an imaginary line drawn through its center. Saturn's axis is not perpendicular (at an angle of 90°) to the planet's path around the sun. The axis tilts at an angle of about 27° from the perpendicular position.

The planet appears to have a hot solid inner core of iron, silicon, oxygen, carbon, and certain other elements.

A layer of highly compressed, liquid metallic hydrogen surrounds the outer core. Above this layer lies a region of hydrogen and helium in a viscous (syruplike) form. The hydrogen and helium gradually become gaseous and merge with the atmosphere, which consists chiefly of the same two elements along with water, ammonia, methane, and other compounds.

A dense layer of clouds covers Saturn. Photographs of the planet show a series of belts and zones of varied colors on the cloud tops. This banded appearance seems to be caused by differences in the temperature and altitude of rising and falling air masses.

Saturn has more mass than any other planet in our solar system except Jupiter. Saturn is about 95 times as massive as Earth. The force of gravity is a little lower on Saturn than on Earth. A 100-pound object on Earth would weigh about 90 pounds on Saturn.

Saturn has a lower density than any other planet in our solar system. It is only about one-eighth as dense as Earth, and about two-thirds as dense as water—that is, a portion of Saturn would weigh much less than an equal portion of Earth, and would float in water.

The tilt of Saturn's axis causes the sun to heat the planet's northern and southern halves unequally, resulting in seasons and temperature changes. Saturn's temperature is always much colder than Earth's, because Saturn is so far from the sun. The temperature at the top of Saturn's clouds averages –285 °F (–175 °C). Temperatures below the clouds are much higher than those at the cloud tops. Saturn gives off about 2 1⁄2 times as much heat as it receives from the sun.

Saturn’s rings surround the planet at its equator but do not touch it. They consist mainly of billions of pieces of ice, ranging from dust-sized grains to chunks that measure more than 10 feet in diameter. The outermost ring, called the E ring, may measure as much as 180,000 miles across. But the rings are so thin that they cannot be seen when they are in direct line with Earth. They vary in thickness from about 660 to 9,800 feet.

Saturn’s ring system includes seven major rings. Many of them feature thin bands of varying brightness called ringlets. Gaps of several thousand miles or kilometers separate most of the major rings. The gaps contain fewer particles than the rings. Some of the gaps feature ringlets. In addition to the major rings, the ring system includes numerous diffuse (scattered) ringlets and small moons.

Astronomers have assigned letters to Saturn’s major rings based roughly on the order of their discovery. From the closest to Saturn to the farthest away, they are the D, C, B, A, F, G, and E rings.

The B and A rings are the brightest rings. A dark gap called the Cassini Division separates the two rings. The gravitational influence of Saturn’s moon Mimas keeps the Cassini Division relatively free of particles. The fainter D and C rings lie inside the B ring. The D, C, B, and A rings each consist of thousands of ringlets.

The fairly bright F ring lies just outside the A ring. The F ring consists of a narrow band of ringlets between the orbits of the moons, Prometheus and Pandora. Astronomers sometimes refer to these satellites/moon as shepherd moons because their gravitational pulls confine or “herd” the particles of the F ring into a narrow band.

The faint G and E rings are much thicker than the inner rings, and their particles are spread more thinly. The E ring consists mainly of microscopic particles. The large moons Mimas, Enceladus, Tethys, Dione, and Rhea orbit Saturn within the E ring. Scientists have determined that some of the ring's particles come from geysers on Enceladus. The G ring is thinner than the E ring and contains larger particles. Astronomers think the ring may come from dust that spreads out from a curved segment of debris called a ring arc that is held in its orbit by the gravity of Mimas.

In 1973, the United States launched a space probe called Pioneer-Saturn to study Jupiter and Saturn. On Sept.1, 1997, the probe reached Saturn. The photographs and data from Pioneer-Saturn led to the discovery of two of the planet’s outer rings. Pioneer-Saturn also found that the planet has a magnetic field, which is almost 1,000 times as strong as that of Earth. This field produces a large magnetosphere (zone of strong magnetic forces) around Saturn.

In 1977, the United States launched two space probes—Voyager 1 and Voyager 2—to study Saturn and other planets. Voyager 1 flew within 77,000 miles of Saturn on Nov. 12, 1980. On Aug. 25, 1981, Voyager 2 flew within 63,000 miles of the planet. The Voyager probes confirmed the existence of Saturn's F ring. They also found that the planet's rings are made up of ringlets. The probes sent back data and photographs that led to the discovery of the existence of nine moons. The Voyager probes determined that the atmosphere of Titan consists chiefly of nitrogen.

In 1997, the United States launched the Cassini probe to study Saturn and its rings and satellites. The probe began orbiting Saturn in 2004. Images taken by Cassini revealed waves of varying density in Saturn’s rings caused by the gravitational pull of the inner satellites. The probe also discovered new details of Saturn’s weather and a great variety of geologic features on Saturn’s largest moons.Cassini carried and released a probe called Huygens, which was built by the European Space Agency. Huygens parachuted through Titan’s hazy atmosphere on Jan. 14, 2005. As the probe fell, it photographed the moon’s surface. The images showed channels apparently carved by flowing liquid methane. After landing, the probe detected liquid methane just below Titan’s surface.

Saturn has 61 moons. Here is a list of some of them from biggest to smallest: Titan, Rhea, Iapetus, Dione, Tethys, Enceladus, Mimas, Hyperion, Phoebe, Janus, Epimetheus, Promrtheus, Pandora, Atlas, Helene, Siarnag, Albiorix, Telesto, Pan, Calypso, Paaliag, Ymir, Kiviug, Tarvos, Ijjrag, Erriano, S/2003 S1, Skathi, Mundilfari, Suttungr, and Thrymr

TITAN

Titan, the largest moon of Saturn, ranks as the second largest moon in the solar system. Titan’s diameter measures about 3,200 miles (5,150 kilometers)—larger than that of the planet Mercury. Measurements of Titan’s density suggest that its interior consists primarily of roughly equal amounts of rock and water ice. Unlike any other moon in the solar system, Titan has a dense atmosphere. Titan’s surface features a complex geography that appears to include dark dunes of organic sand, mountains covered by clouds of methane, volcanoes of water and ammonia ice, and systems of methane and ethane lakes and seas. Methane rains and eruptions of water from inside the moon seem to have shaped Titan’s surface, much as Earth’s surface has been shaped by erosion and volcanic activity.

TETHYS

Tethys, the fifth largest moon of Saturn, features a giant impact crater and a large trench that nearly encircles the moon. Tethys’s surface also contains many smaller craters, regions of grooved terrain, and flat plains that appear to have been smoothed by ice flows. The moon consists almost entirely of water ice and may once have had a liquid water interior. Tethys’s diameter measures roughly 660 miles (1,060 kilometers). The moon orbits Saturn every 1.89 days at an average distance of about 183,100 miles (294,700 kilometers). A vast trench called Ithaca Chasma stretches more than 1,200 miles (2,000 kilometers) across Tethys’s surface. The trench measures 2 to 3 miles (3 to 5 kilometers) in depth and up to 60 miles (100 kilometers) in width. Some scientists think that Ithaca Chasma formed as Tethys’s liquid interior froze.

RHEA

Rhea, the second largest moon of Saturn, has an icy surface marked by bright craters and networks of light streaks. Rhea's surface consists primarily of water ice. Measurements of Rhea’s density suggest that the moon has a rocky core. Rhea’s diameter measures 949 miles (1,528 kilometers). The moon orbits Saturn every 4.52 days at an average distance of around 327,500 miles (527,000 kilometers).

DIONE

Dione, the fourth largest moon of Saturn, has an icy surface marked by impact craters and bright, wispy streaks. Dione’s diameter measures about 696 miles (1,120 kilometers). The moon orbits Saturn every 2.74 days at an average distance of around 234,500 miles (377,400 kilometers).

IAPETUS

Iapetus, the third largest moon of Saturn, has a surface marked by distinct light and dark halves. No other body in the solar system displays such a bold contrast. Iapetus’s diameter measures roughly 900 miles (1,450 kilometers). The moon orbits Saturn every 79.3 days at an average distance of about 2,213,000 miles (3,561,000 kilometers).