Saturn Up Close What’s in a Name? - World BookSaturn Up Close One of Saturn’s 60 moons, Titan,...

Saturn Up Close 51

Saturn, like Jupiter, is a gas giant. Saturnis not as large as Jupiter—but it is manytimes larger than Earth. Whereas Jupiter’srings are so faint that they cannot be seenfrom Earth, Saturn’s are wide and bright.Many people think Saturn is the mostbeautiful object in the solar system.

Probes to SaturnNASA’s Pioneer 11 was the first spaceprobe to reach Saturn. After passing byJupiter, Pioneer 11 flew within 13,000miles (20,900 kilometers) of Saturn onSeptember 1, 1979.

Saturn was the next stop after Jupiter onthe Voyager’s “Grand Tour.” Voyager 1reached Saturn in 1980. Voyager 2 reachedthe planet in 1981. The Voyager probesreturned detailed photos of Saturn andseveral of its moons. The photos showeddetails of Saturn’s rings never before seen.

The Cassini probeEuropean space agencies cooperated with NASA toplan a special space mission to Saturn and its moons.The mission became known as the Cassini mission.The Cassini probe was launched from Earth in 1997.In July 2004, it went into orbit around Saturn.

Cassini sent back a wealth of data about Saturnand, of course, many detailed photos. It showedSaturn’s huge ring system in greater detail than everbefore. It also detected enormous thunderstorms andstorms similar to hurricanes in Saturn’s atmosphere.

Unmasking TitanSaturn has more than 60 moons. The largest, Titan,has a dense atmosphere, unlike all other moons in thesolar system. The atmosphere is mostly nitrogen.Titan also shows evidence of having seasons.

The Cassini probe carried a smaller probe, Huygens(HOY gehns). In 2005, Cassini released Huygens, whichlanded on Titan’s surface. It sent back thrillingimages, including images of lakes and river systemsthat look much like those on Earth. However, they arefilled with liquid ethane and methane. On Earth, thesechemicals typically exist in the form of a gas. Theybecome liquid only at very low temperatures. TheHuygens probe reported atmospheric temperatures onTitan’s surface of –290 ºF (–178 ºC).

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Saturn is the sixth planet from the sun.The first of several Earth probes reachedSaturn in 1979.

What’s in a Name?The Cassini probe was named for GiovanniDomenico Cassini (1625–1712), an Italian-born French astronomer. Cassini discoveredfour of Saturn’s moons and described a gapin Saturn’s ring system. The Huygens probewas named for Christiaan Huygens (1629–1695), a Dutch scientist who discoveredTitan and contributed to the development ofmodern telescopes.

Saturn has features thatsomewhat resemble

storm systems on Earth. In2004, the Dragon Storm,shown in a false-colorphotograph, generatedlightning 10,000 times asstrong as lightning on Earth.

Saturn Up Close

One of Saturn’s 60 moons,Titan, ranks as the secondlargest satellite in the solarsystem. It has lakes and riversystems that look much likethose on Earth but are filledwith liquid ethaneand methane.

Saturn’s rings are made up ofchunks of ice and rock. Someof the chunks are tiny.Others may be as big as atruck or even bigger.

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