1. 4.5 The Outer Planets What Do the Outer Planets Have in Common?
What Are the Characteristics of Each Outer Planet?

3. What Do the Outer Planets Have in Common?
Large
Gas giants (no solid surface)

4. Composition Hydrogen and helium Ices of ammonia and methane
Strong gravitational forces (due to their size) keep these gases from escaping
Much of the material in gas planets is actually liquid because the pressure inside the planet is so high
The outer layers are extremely cold
Temperature increases inward with pressure

5. Moons and Rings All outer planets have many moons
Jupiter: at least 63
Saturn: at least 61
Uranus: at least 27
Neptune: at least 13
All outer planets have rings
Thin disks of small particles of ice and rock
Saturn’s rings are largest and most complex

6. What Are the Characteristics of Each Outer Planet?
Scientists are constantly discovering new information about these planets and moons (using telescopes and space probes)

7. Jupiter Largest and most massive planet
Mass is 2 ½ times more than all of the other planets combined

8. Jupiter’s Atmosphere Thick atmosphere (hydrogen and helium)
Great Red Spot: Storm larger than Earth!
Similar to a hurricane
Never ending
20,000 km long and 12,000 km wide

9. Jupiter’s Structure Dense core of rock and iron at its center
Pressure is 30 times greater than on the surface
It has a thick mantle of liquid hydrogen and helium

10. The Moons of Jupiter

11. Ganymede: Jupiter’s largest moon. (Larger than Mercury)
Surface has dark and bright areas

12. Callisto:
Second largest
Less ice
Most craters

13. Io:
Not icy
May have 300 active volcanoes

14. Europa:
Ice
Liquid water below the ice (possibly)

15. Saturn
2nd largest planet
Thick atmosphere (hydrogen and helium)

16. Saturn’s Rings Made up of chunks of ice and rock going around Saturn
Some are kept in place from gravity of tiny moons

17. Saturn’s Moons Titan (largest…larger than Mercury)
Thick atmosphere (nitrogen and methane)
Some features formed from flowing liquid
Mimas and Tethys: craters and trenches
Enceladus: Ice and water erupt in geysers
Phoebe: ring of material found

18. Uranus 4 times diameter of Earth
Looks blue-green due to methane in atmosphere
Rings

19. Uranus’s Moons
The 5 largest moons have icy, cratered surfaces

20. A Tilted Planet
Tilted at an angle of about 90 degrees from the vertical
The tilt is due to an object hitting Uranus and knocking it on its side
Rotation = 17 hours

21. Neptune Similar to Uranus in size and color Blue and cold
Atmosphere contains visible clouds
Interior is hot (forming clouds and storms at the surface)

22. Neptune’s Atmosphere Great Dark Spot (about the size of Earth)
Scientists think it is probably a giant storm that lasted a short period of time

23. Neptune’s Moons 13 moons Triton (largest) Thin atmosphere
Nitrogen ice over south pole

24. THE END