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Saturn |
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-- Saturn, named after the Roman god of agriculture. Saturn, named after the Roman god of agriculture, is the sixth planet from the Sun. It is the second largest planet in our solar system, only Jupiter is larger. Composed mostly of hydrogen and helium, Saturn is also the second largest of the "gas giant" planets, which include Saturn, Jupiter, Neptune, and Uranus. Saturn is so large that at least 740 planets the size of Earth could fit inside of it. The diameter at its equator is almost 10 times that of our planet and its mass is about 95 times greater than the Earth's. Saturn's magnetic field is 1000 times stronger than the Earth's. Saturn is the lightest planet per unit of volume, thus, it has a lower density than any other planet. In fact, if there were a swimming pool big enough, Saturn would float in it. This is because it's made of materials that are lighter than water, namely hydrogen and helium. One of the brightest objects in the sky at night, Saturn appears yellowish from our planet. Saturn is famous for its beautiful rings, which can easily be seen through binoculars. In 1610, Galileo became the first person to see the planet's rings. He used a primitive telescope. He mistakenly thought they were attached to the planet, so he called them handles. However, Galileo was wrong about Saturn's rings; tens of thousands of rings surround the planet, but do not actually touch it. They occur in groups and extend from about 4,300 miles to as far as 46,000 miles from the planet's atmosphere. Gaps between the groups of rings are called Cassini Divisions. The rings appear to be solid, but they are really made of dust and pieces of rock and ice that range in size from small dust-sized particles to house-sized particles. Saturn's rings are thousands of miles wide, but in places are no wider than a school playground. A dense layer of cloud bands covers Saturn and an atmospheric haze covers the clouds. Differences in temperature and altitude probably cause the bands. Helium, a heavier element, slowly sinks through the planet's hydrogen towards its center. As this happens, friction is created. This and heat from when the planet was formed cause Saturn to give off twice as much heat as it receives from the Sun. Saturn has at least 18 moons. Titan, one of the planet's moons, is larger than the planet Mercury. It is the only moon in our solar system that has a substantial atmosphere. Titan's atmosphere is made of nitrogen and methane and exerts about 1-1/2 times as much surface pressure as our planet's atmosphere. Titan is about half rock and half ice. Saturn orbits the Sun at an average distance of 888 million miles (1429 million km). It takes about 10,759 Earth days for Saturn to travel one time around the Sun - that's about 29 1/2 Earth-years! However, Saturn is the second fastest rotating planet. Only Jupiter rotates faster. In fact, Saturn rotates once every 10 hours 39 minutes. Because its axis is tilted, Saturn experiences seasons. However, one season on Saturn is equivalent to about 7 1/2 years on our planet. Saturn's temperature is colder than the Earth's because it is farther from the Sun. The United States has sent three spacecraft to Saturn. Pioneer 11 visited the planet in September 1979, Voyager visited in November 1980, and Voyager 2 visited in August 1981. Voyager 1 and Voyager 2 gave us more information about the planet's rings.
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