Saturn, shown in Figure 1.1, is famous for its beautiful rings. Although all the gas giants have rings, only Saturns can be easily seen from Earth. In Roman mythology, Saturn was the father of Jupiter. Saturns mass is about 95 times the mass of Earth, and its volume is 755 times Earths volume, making it the second largest planet in the solar system. Saturn is also the least dense planet in the solar system. It is less dense than water. What would happen if you had a large enough bathtub to put Saturn in? Saturn would float! Saturn orbits the Sun once about every 30 Earth years. Like Jupiter, Saturn is made mostly of hydrogen and helium gases in the outer layers and liquids at greater depths. The upper atmosphere has clouds in bands of different colors. These rotate rapidly around the planet, but there seems to be less turbulence and fewer storms on Saturn than on Jupiter. One interesting phenomenon that has been observed in the storms on Saturn is the presence of thunder and lightning (see video, below). The planet likely has a small rocky and metallic core. This image of Saturn and its rings is a composite of pictures taken by the Cassini orbiter in 2008
In 1610, Galileo first observed Saturns rings with his telescope, but he thought they might be two large moons, one on either side of the planet. In 1659, the Dutch astronomer Christian Huygens realized that the features were rings (Figure 1.2). Saturns rings circle the planets equator and appear tilted because Saturn itself is tilted about 27 degrees. The rings do not touch the planet. The Voyager 1 and 2 spacecraft in 1980 and 1981 sent back detailed pictures of Saturn, its rings, and some of its moons. Saturns rings are made of particles of water and ice, with some dust and rocks (Figure 1.3). There are several gaps in the rings that scientists think have originated because the material was cleared out by the gravitational pull within the rings, or by the gravitational forces of Saturn and of moons outside the rings. The rings were likely formed by the breakup of one of Saturns moons or from material that never accreted into the planet when Saturn originally formed.
Most of Saturns moons are very small, and only seven are large enough for gravity to have made them spherical. Only Titan is larger than Earths Moon at about 1.5 times its size. Titan is even larger than the planet Mercury. Scientists are interested in Titan because its atmosphere is similar to what Earths was like before life developed. Nitrogen is dominant and methane is the second most abundant gas. Titan may have a layer of liquid water and ammonia under a layer of surface ice. Lakes of liquid methane (CH4 ) and ethane (C2 H6 ) are found on Titans surface. Although conditions are similar enough to those of early Earth for scientists to speculate that extremely A color-exaggerated mosaic of Saturn and its rings taken by Cassini as Saturn eclipses the Sun. A close-up of Saturns outer C ring show- ing areas with higher particle concentra- tion and gaps. This composite image compares Saturns largest moon, Titan (right) to Earth (left). Click image to the left or use the URL below. URL:
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--> a) the only planet with rings that we can see from earth. b) the densest planet. c) the most massive planet. d) all of these.
if you could find a bathtub big enough, you could put enough water to float saturn in it.
--> a) true b) false
saturns rings are connected to the planet.
a) true --> b) false
what makes up saturns rings?
a) water b) ice c) dust and rocks --> d) all of the above
enceladus could be home to life because it has
--> a) internal heat. b) methane. c) water ice. d) all of the above.
a) has a great red spot like jupiter. b) has clouds in different colored bands. --> c) has thunder and lightning. d) all of the above.
a) were first seen by galileo through his telescope. b) appear tilted because saturn is tilted. c) have gaps due to the gravitational pull of saturn or its moons. --> d) all of the above.
saturns atmosphere is just as stormy s jupiters.
a) true --> b) false
scientists are interested in titan because
a) it is very likely to have microbial life. --> b) its atmosphere is similar to earths early atmosphere. c) it is the same size as earth. d) all of these.
scientists are certain that saturns rings formed when one if its moons broke apart.
a) true --> b) false
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