Saturn

Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Named after the Roman god Saturn, its astronomical symbol (♄) represents the god's sickle. Saturn is a gas giant with an average radius about nine times that of Earth. While only one-eighth the average density of Earth, with its larger volume Saturn is just over 95 times more massive than Earth.

Saturn's interior is probably composed of a core of iron, nickel and rock (silicon and oxygen compounds), surrounded by a deep layer of metallic hydrogen, an intermediate layer of liquid hydrogen and liquid helium and an outer gaseous layer. The planet exhibits a pale yellow hue due to ammonia crystals in its upper atmosphere. Electrical current within the metallic hydrogen layer is thought to give rise to Saturn's planetary magnetic field, which is slightly weaker than Earth's and around one-twentieth the strength of Jupiter's. The outer atmosphere is generally bland and lacking in contrast, although long-lived features can appear. Wind speeds on Saturn can reach 1,800 km/h (1,100 mph), faster than on Jupiter, but not as fast as those on Neptune.

Saturn has a prominent ring system that consists of nine continuous main rings and three discontinuous arcs, composed mostly of ice particles with a smaller amount of rocky debris and dust. Sixty-two known moons orbit the planet; fifty-three are officially named. This does not include the hundreds of "moonlets" within the rings. Titan, Saturn's largest and the Solar System's second largest moon, is larger than the planet Mercury and is the only moon in the Solar System to retain a substantial atmosphere.

Read more about Saturn:  Physical Characteristics, Atmosphere, Magnetosphere, Orbit and Rotation, Planetary Rings, Natural Satellites, History of Exploration, Observation, In Culture

Famous quotes containing the word saturn:

    Test of the poet is knowledge of love,
    For Eros is older than Saturn or Jove;
    Never was poet, of late or of yore,
    Who was not tremulous with love-lore.
    Ralph Waldo Emerson (1803–1882)

    The forehead and the little ears
    Have gone where Saturn keeps the years;
    The breast where roses could not live
    Has done with rising and with falling.
    Edwin Arlington Robinson (1869–1935)

    It is marvelous indeed to watch on television the rings of Saturn close; and to speculate on what we may yet find at galaxy’s edge. But in the process, we have lost the human element; not to mention the high hope of those quaint days when flight would create “one world.” Instead of one world, we have “star wars,” and a future in which dumb dented human toys will drift mindlessly about the cosmos long after our small planet’s dead.
    Gore Vidal (b. 1925)