1. 14.4 The Solar System Outer Planets (page 562)

2. Planets There are 8 planets: Mercury Venus Earth Mars Jupiter Saturn
Uranus (YOOR uh nus)
Neptune
Pluto --- dwarf
Terrestrial Planets
Gas Giants
**You are responsible for knowing the planets in order!!!!
A good way to remember the order is through a pneumonic. (My Very Energetic Mom Just Sent Us Nine Pizzas)

3. The Gas Giants
The last four outer planets are much larger and more massive than Earth, and they do not have solid surfaces.
For these reasons they are called the “Gas Giants”
They have many moons.
They are also surrounded by a set of rings.

4. Jupiter The largest planet: 318x Earth
Jupiter is the fourth brightest object in the sky (after the Sun, Moon and Venus)
Galileo discovered four of Jupiter’s moons in 1610
Jupiter has 63+ moons (Ganymede is the largest with a mass 2x that of Earth’s moon)

5. Jupiter Thick atmosphere of hydrogen and helium
The atmosphere has many colorful bands of swirling clouds
The Great Red Spot: a giant area of swirling clouds many times bigger than Earth (a storm similar to a hurricane)
Jupiter is a gas planet and does not have a solid surface (though it most likely has a solid core 10-15x the mass of Earth)

6. Jupiter
Jupiter radiates more energy into space than it receives from the Sun!!!!!
It’s interior is hot, due to gravitational compression.
It has a huge magnetic field.
It has rings, but much fainter and smaller than Saturn’s.

7. Saturn Saturn is the 2nd largest planet
It is easily visible in the night sky
It is the least dense of all the planets. It is less dense than water.
Its atmosphere is about 75% hydrogen; 25% helium
It probably has a rocky core

8. Saturn
There are 100s of rings that are made up of ice and rock, each traveling in its own orbit
The rings are very thin (less than 1 km)
Saturn has 30 moons: Titan (the largest), Tethys, Iapetus, Dione, and Rhea.

9. Uranus 4x the diameter of Earth
It is a bluish color due to traces of methane (CH4) in its atmosphere.
Twice as far away from the Sun as Saturn (next to it).
Discovered in 1781by William Herschel
Uranus’s axis of rotation is tilted at an angle of about 90 degrees from vertical

10. Uranus Uranus is the coldest of all the planets
It is also the second-least dense planet after Saturn
Its atmosphere is about 83% hydrogen, 15% helium, 2% methane
Like other gas planets, Uranus has rings
Uranus has 27 moons (21 named, 6 unnamed)

11. Neptune Neptune is the fourth largest planet
It is often called the “cold, blue planet”
It also has rings.
It is possibly shrinking and growing warmer
Neptune possibly has a rocky core

12. Neptune
Neptune's most prominent feature was the Great Dark Spot (left) in the southern hemisphere. It was about half the size as Jupiter's Great Red Spot (about the same diameter as Earth).
Neptune has 13 known moons.
Neptune was discovered in 1846 due to a mathematical prediction involving Uranus

13. Pluto Only has 1 moon: Charon
Pluto has a solid surface (probably rock and ice) is less than 2/3 the size of Earth’s moon.
Pluto is not considered a planet
Orbit very elliptical
Not like gas giants
Just rock and ice

14. Assignment
Do the review questions for 14.4 on page 569