Chapter 27.4 The Outer Planets

Std. 1a- Students know how the differences and similarities among the sun, the terrestrial planets, and the gas planets may have been established during the formation of the solar system

Objective 1: Identify the differences between the outer planets and the terrestrial planets

Objective 2: Compare the characteristics of the outer planets

Objective 3: Explain why Pluto is different from the other 8 planets

The Outer Planets

• The 5 Planets farthest from the sun are:

5) Jupiter

6) Saturn

7) Uranus

8) Neptune

9) Pluto• Asteroid belt - A ring of

debris that separates the inner and outer planets

Gas Giants

• Gas giants are much larger than terrestrial planets (much less dense)

• Thick atmosphere = mostly hydrogen and helium

• Cores = rock and metal • All four gas giants have ring systems made of

dust and ice debris

Jupiter

• 5th planet from the sun • Largest planet 300x

larger than Earth• Orbits the sun every

12 years • Rotates every 9hrs 50

min. (fastest) • At least 60 moons • Several thin rings

Jupiter’s Atmosphere

• Hydrogen and helium makes up 92% of the atmosphere

• Rapid rotation causes gases to swirl around the planet and form bands – Great Red Spot – giant storm

• Average temperature -160 ° C

Jupiter’s interior

• Jupiter’s interior has higher temperature and pressure than Earth’s interior

• Interior is a liquid (metallic hydrogen) surrounding a solid, rocky, iron core

Objective 1: Identify the differences between the outer planets and the terrestrial planets

• What is the ring of debris that separates the inner and outer planets?– Asteroid Belt

• Gas giants atmosphere’s are made of mostly…– Hydrogen and Helium

• What is the name of the storm on Jupiter?– Great Red Spot

• What do gas giants have that terrestrial planets don’t? – Rings

Saturn

• 6th planet from the sun • Orbital period is 29.5 years • Cloud temperature -176 ° C • At least 30 moons, Titan (largest moon) is half

the size of Earth • Made of hydrogen & helium (rocky iron core)

Saturn’s rings

• Most complex system of rings of all the gas giants – made of billions of ice and dust particles – Rotates every 10h 30 min

• Fast rotating & low density causes Saturn to bulge at the equator

Uranus

• 7th planet from the sun • 3 billion km away

(difficult to study )• 24 moons• 11 thin rings • Orbits every 84 yrs

Uranus rotation

• Axis is parallel to the plane of it’s orbit–Most planets rotate

perpendicular• Rotates every 17 hrs. • Atmosphere - hydrogen & helium • Blue/green color indicates

presence of methane• -214 °C core of rock and melted

elements

Neptune

• 8th planet • Same size and mass as

Uranus • Orbital period is nearly

164 years • Rotates every 16 hrs. • Has at least 8 moons &

possibly 4 rings

Neptune’s Atmosphere

• Consists of hydrogen, helium & methane • Solar systems strongest wind > 1,000 km/h• The Great Dark Spot is a storm as big as Earth • Cloud temperature = -225°C

Objective 2: Compare the characteristics of the outer planets

• What are Saturn’s rings made of?– Billions of dust and particles

• What is the name of the storm on Neptune?– The Great Dark Spot

• What’s unique about Uranus’s rotation?– It rotates almost parallel to the plane of it’s orbit

• What gives Uranus’s it’s blue/green color?–Methane

Pluto

• Dwarf planet • Elongated orbit (sometimes in Neptune’s orbit)• Made of frozen methane, rock & ice • Very different than the gas giants (may not be

an actual planet)

Objects Beyond Pluto

• Kuiper Belt - A region of the solar system beyond Neptune’s orbit which contains small bodies made of ice– Pluto may be the largest body of the Kuiper Belt

Exoplanets

• Exoplanets - planets that orbit other stars

• They DO NOT orbit the sun in our solar system

Objective 3: Explain why Pluto is different from the other 8 planets

• What makes up Pluto?–Frozen methane, rock and ice

• Why is Pluto not considered an actual planet?–Very different than the gas giants

• Pluto may be the largest body of the…–The Kuiper Belt

• What are planets that orbit other stars? – Exoplanets