sixth planet from the sun

Saturn

In Roman mythology, Saturn is the god of agriculture and time. Saturn is the root of the English word "Saturday"

In Greek mythology, Cronus was the son of Uranus and Gaea. He lead his brothers and sisters, the Titans, in a revolt against their father and became the king of the gods. He married the Titan Rhea.

They had a total of six children, but Cronus had a bad habit of eating his newborn children, to prevent them from one day overthrowing him as king of the gods. Finally, at the birth of her last child, Zeus, Rhea tricked him into swallowing a rock instead. Zeus then beat his father, with the help of his brothers and sisters. The Romans adopted Cronus as the god Saturn.

History of Saturn Observation

The oldest written records documenting Saturn are attributed to the Assyrians. Around 700 B.C., they described the ringed planet as a sparkle in the night and named it "Star of Ninib."

Like the Greeks, in Roman mythology Saturn was also the god of agriculture. It was in his honor that in December the Saturnalia festival was celebrated, a seven-day affair that became ancient Rome's most popular festivity.

At first Galileo assumed Saturn was a group of three close-knit planets, with two smaller ones on each side of a bigger planet. Two years later, he noticed that the two smaller planets had vanished and Saturn was now all by itself. We know now that the rings seem to disappear as our view of the ring plane shifts. A couple of years later, Galileo's observations became even more confusing when the rings reappeared, in their places next to Saturn.

Confusion reigned until Christiaan Huygens, a Dutch astronomer, developed the concept of a planetary ring system in 1659. Using an improved telescope - one that could magnify images by 50 times -- Huygens theorized the rings to be solid, thin and flat

In 1676, Giovanni Cassini, an Italian astronomer who eventually became a French citizen, was able to see the biggest gap within the ring system, now known as the Cassini Division or the Cassini Gap. Cassini and Huygens also discovered moons around the ringed planet, and the known number of satellites orbiting Saturn has been growing ever since.

Finding Saturn

Saturn is the sixth planet from the Sun and the second largest:

Saturn is about 74,898 miles (120,536 km) in diameter (at the equator at the cloud tops). This is about 9.4 times the diameter of the Earth. 764 Earths could fit inside a hollowed-out Saturn.

Each day on Saturn takes 10.2 Earth hours. A year on Saturn takes 29.46 Earth years; it takes 29.46 Earth years for Saturn to orbit the sun once.

Saturn is 9.539 AU, on average, from the sun, about 9 and a half times as far from the Sun as the Earth is.

Saturn is about 97% Hydrogen gas, about 3% helium gas and about 0.05% methane, plus ammonia.

Saturn’s Atmosphere

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There are three clouddecks on Saturn, and each one is composed of different molecules. There is a clouddeck of ammonia clouds, a clouddeck of ammonia hydrosulfide clouds, and a clouddeck of water clouds (H2O).

Motions in the cloud patterns indicate that, like Jupiter, the basic weather of Saturn can be described as a striped pattern of winds.

The clouds of Saturn are much less colorful than those of Jupiter. This is because the composition of Saturn's atmosphere includes more sulfur. This adds to Saturn's overall yellow appearance

Saturn is the most oblate (flattened) planet in our Solar System. It has a equatorial diameter of 74,898 miles (120,536 km) (at the cloud tops) and a polar diameter of 67,560 miles (108,728 km). This is a difference of about 10%. Saturn's flattened shape is probably caused by its fast rotation and its gaseous composition.

Near the equator, tremendous winds blow at 1,100 mph (500 meters per second) toward the east. The clouds in the atmosphere are cold, thick and uniform in shape.

Saturn is a gaseous planet with a rocky core, a liquid metallic hydrogen layer above the core, and a molecular hydrogen layer above that. The hot, heavy, rocky core has a radius possibly three times the radius of the Earth.

Saturn has a strong magnetic field (less than Jupiter's, but still very strong). Saturn's magnetic field is probably generated by electrical current in conductive layers near the quickly-rotating planet's core. Because of this strong magnetic field, there are abundant auroras on Saturn and radios emissions from it.

Saturn radiates 79% more energy than it receives from the Sun, probably heat from its hot core.

The mean temperature on Saturn (at the cloud tops) is 88 K (-185° C; -290° F).

Saturn is the only planet in our Solar System that is less dense than water. Saturn would float if there were a body of water large enough!

A 100 pound person would only weigh 108 pounds on Saturn.

Saturn's mass is about 5.69 x 1026 kg. Although this is 95 times the mass of the Earth, the gravity on Saturn is only 1.08 times the gravity on Earth.

RINGS

Saturn's bright rings are made of ice chunks (and some rocks) that range in size from the size of a fingernail to the size of a car. Although the rings are extremely wide (almost 185,000 miles = 300,000 km in diameter), they are very thin (about 0.6 miles = 1 km thick).

SPACECRAFT VISITSSaturn has been visited by Pioneer 11 (in 1979) and by Voyager 1 and Voyager 2. Cassini, a spacecraft named for the divisions in Saturn's rings, is on the way and will arrive in 2004

http://soc.jpl.nasa.gov/history.cfm

http://www.nineplanets.org/saturn.html

http://saturn.jpl.nasa.gov/kids/fun-facts-history.cfm

http://www.enchantedlearning.com/subjects/astronomy/planets/saturn/saturninside.shtml