SaturnDiscovering Saturn:

“The Real Lord of the Rings”

Prepared by :Kristine Ann B. de

Jesus

Basic Facts• 6th Planet from the Sun• 2nd Largest Planet in the Solar

System• 7 thin, flat rings• 62 Moons

Saturn the Name

• Roman god of agriculture and harvest

• Father of Ceres, Jupiter, Pluto, and Neptune

• Ruled during the Golden Age of Men

• Saturn represents limits of control as it was thought to be the limit of the Solar System

Ancient Observations• Farthest planet prehistoric astronomers knew

(Distance from the sun: 9.5 times as far as Earth) (1 Solar Revolution: 29.5 earth years)• Used in mythology• It was the planet that can be seen by Earth with

the naked eye, but the rings cannot.

Discovery

• Galileo discovered rings 1610, though believed they were moons on either side

• Christian Huygens first coined “Rings” 1665

Where is Saturn Located?• It orbits the Sun at a distance of

about 1.4 billion km (870 million mi). Saturn is about 9.5 times as far from the Sun as the Earth.• Saturn is almost twice as far from

the Sun as is Jupiter, the fifth planet in the Solar System.

How Big is Saturn?

• 2nd largest planet in the Solar System

• 95 Earth masses• “Gas Giant” along with

Jupiter, Uranus and Neptune

• Diameter 120,540km (10x Earth)

If Saturn is so much more massive than Earth, Why is it said that Saturn could

float in water?

• Lowest density of all the planets• 1/10 the density of Earth• 2/3 dense as water• Saturn would float in water!

WHAT IS SATURN MADE OF?• Primarily a ball of gas with no

solid surface.• 94% Hydrogen, 6% Helium,

small amounts of methane (CH4) and ammonia (NH3)

• Detailed analysis of Saturn’s gravitational field leads to astronomers to believe that the deepest interior of Saturn must consist of a molten rock core. (same size as Earth but more massive)

Saturn’s Surface• Saturn is a giant ball of gas

• Believed to have no solid surface• Inner core of iron and rocky material• Outer core of ammonia, methane, and

water• Liquid metallic hydrogen surrounds outer

core• Hydrogen and helium in a viscous form

Saturn’s Atmosphere• The surface and atmosphere

merge (hydrogen and helium)

• Dense clouds cover Saturn• Difference in temperature

and altitude cause patterns and color differences in cloud tops

• Hexagon clouds at North Pole

Saturn’s Orbit

• Aphelion ~ 10.1 AU ; Perihelion ~ 9.0 AU• Period of Orbit – 29.46 Earth years • Axis tilt of 27 degrees• Eccentricity of .056• Rotation is 2nd fastest of known planets• Saturn rotates ~ 10 hours 39 minutes

How Long is a Year on Saturn?

• It takes 29.5 Earth days to travel once around the sun. So, 1 Saturn year is about 30 Earth Years.

Shape of Saturn

• Rapid rotation causes the planet to bulge• Oblate spheroid – flattened at poles and

bulges at equator• Rings

Why isn’t Saturn the same color as Jupiter?

Saturn: World of white and pastel yellow cloud layers

Jupiter: Bright yellows, oranges, and reds in exotic swirls and storms

Near the top of the atmosphere, ammonia becomes cold enough to crystallize into ice particle cloud. But Saturn is colder than Jupiter, so the colorful ammonia cloud are deeper in the atmosphere.

Saturn’s Rings• Discovered by Galileo (1600s)• Rings tilt at same angle as

equator• ~20m thick• 93% water ice composition, 7%

amorphous carbon• 7 rings made up of thousands of

ringlets, made up of billions of ice particles

• Particles range in size from dust to a car

2 Main Ring Theories• Theory 1

• Remnants of destroyed moon of Saturn

• Theory 2• Rings left over from original nebular material that

formed Saturn

• Some ice comes from the moon Enceladus’ ice volcanoes

Temperature• Tilt of axis causes seasons on

Saturn• Each season = 7.5 Earth

years (Saturn takes 29x longer than Earth to revolve)

• Top of clouds is -175 degrees C (-285 F)

• Below clouds is hot – planet gives off 2.5x the heat it receives from the Sun

Moons• 62 Moons• Largest, Titan (diameter 5,150km) is larger

than Mercury and Pluto and contains an atmosphere

SPACE EXPLORATIONS

1.Pioneer 11 in 19792.Voyagers 1 3.Voyagers 2 (1981-1982)4.Cassini-Huygens in 2004-“1st

Spacecraft to land on a moon other than Earth’s moon.”

PIONEER 1

VOYAGER 1 & 2