1. The Outer Planets
Chapter 23, Section 3

2. Jupiter: Giant Among Planets
Jupiter has a mass that is 2 ½ times greater than the mass of all other planets and moons combined
If Jupiter had been about 10 times larger, it would have become a star
One rotation around its axis take 10 Earth hours
The most striking feature of Jupiter is its Great Red Spot, it is a cyclonic storm in the upper atmosphere
Jupiter’s hydrogen-helium atmosphere also contains small amounts of methane, ammonia, water, and sulfur compounds
Due to immense pressures within the atmosphere, Jupiter is thought to be a gigantic ocean of liquid hydrogen
Jupiter also has a faint system of rings surrounding the planet, not discovered until Voyager 1 flew past in 1979

3. Jupiter’s Atmosphere

4. Jupiter’s Moons
Jupiter’s satellite system, consisting of 28 moons discovered so far, looks like a mini solar system
The four largest moons (Io, Europa, Ganymede, and Callisto) were discovered by Galileo
Io is one of three known volcanically active bodies in our solar system (Neptune’s moon Triton is another)
The largest of the moons is Ganymede
Europa is covered with ice and shows many linear features
Callisto is heavily cratered and greatly resembles Earth’s moon

5. Jupiter and its Moons

6. Saturn: The Elegant Planet
The most prominent feature of Saturn is its system of rings
Saturn’s atmosphere is very active, with wind speeds up to 1500 kilometers per hour
Large “cyclonic” storms occur in the atmosphere
The main rings of Saturn (A and B) are very dense and contain many “moonlets” that often collide with each other
Saturn’s faintest ring (E) is composed of very fine particles that are spread apart
Saturn’s satellite system consists of 31 moons (Titan is the largest and has an atmosphere that obscures its surface from view)
Saturn’s moon, Enceladus, was found to emit liquid geysers

7. Saturn and its Moons

8. Saturn’s Rings

9. Uranus: The Sideways Planet
Instead of being generally perpendicular to the plane of its orbit, Uranus’s axis of rotation lies nearly parallel with the plane of its orbit
Uranus has a set of at least nine distinct rings
Uranus has five large moons, and many smaller ones, that are very varied in their geology: deep canyons, linear scars, large-smooth areas on otherwise cratered surfaces

10. Uranus

11. Neptune: The Windy Planet
Winds exceeding 1000 kilometers per hour encircle Neptune, making it one of the windiest places in the solar system
It has an Earth-size storm called the Great Dark Spot
There are white, cirrus-like clouds that occupy a layer about 50 kilometers above the main cloud deck, thought to be frozen methane
Triton, Neptune’s largest moon, exhibits retrograde motion, indicating that it formed separately from Neptune and was gravitationally captured

12. Neptune

13. Pluto: Planet X
Pluto lies on the fringe of the solar system, almost 40 times farther from the sun than Earth
Because of its great distance, and slow orbital period, it takes Pluto 248 Earth-years to orbit the sun
Pluto’s orbit is highly eccentric, causing it to occasionally travel inside the orbit of Neptune, where it resided from 1979 through February 1999
In 1978, the moon Charon was found to be orbiting Pluto
The average temperature on Pluto is estimated at -210ºC
In 2006, Pluto’s status as a planet was revoked, it is now considered a dwarf planet along with many other Kuiper belt objects

15. Assignment Read Chapter 23, Section 3 (pg. 654-659)
Do Section 23.3 Assessment #1-7 (pg. 659)