1. The Outer Planets Section 14.4

2. Standard 0 8.4.e. Students know the appearance, general composition, relative position and size, an motion of objects in the solar system, including planets, planetary satellites, comets, and asteroids.

3. Introduction 0 The most obvious difference between Jupiter and other terrestrial planets: 0 IT’S SO BIG! 0 Like other giant planets, Jupiter has no real surface, just a core buried deep within the planet.

4. Gas Giants and Pluto 0 The four outer planets – Jupiter, Saturn, Uranus, and Neptune – are much larger and more massive than Earth, and they do not have solid surfaces 0 Gas Giants: because these four Planets are so large and are composed of gas, they are called the gas giants.

5. Gas Giants and Pluto 0 Like the sun, the gas giants have atmosphere composed mainly of hydrogen and helium 0 Hydrogen and Helium are actually in a liquid state. 0 Ring: A thick disk of small particles of ice and rock

6. Jupiter 0 Jupiter is the largest and most massive planet. 0 Jupiter’s Atmosphere 0 Thick and made mostly of hydrogen and helium. 0 Great Red Spot: storm larger than Earth 0 There is no land to weaken the storm, so it goes on forever

7. Jupiter 0 Jupiter’s Structure 0 Dense core of rock and iron at its center 0 Pressure at Jupiter’s core is estimated to be about 30 million times greater than the pressure at Earth’s surface 0 Jupiter’s Moons 0 Galileo discovered Jupiter’s 4 largest moons 0 Io, Europa, Ganymede, Castillo

8. Saturn 0 Second largest in the solar system 0 Thick atmosphere of hydrogen and helium 0 Density is less than water 0 Saturn’s Rings 0 Saturn has the most spectacular rings of any planet. Saturn’s rings are broad and thin, like a CD or DVD.

9. Saturn 0 Saturn’s Moons 0 Titan is larger than the planet Mercury 0 Titan has an atmosphere so thick that little light can pass through it.

10. Uranus 0 4x the diameter of Earth 0 Uranus looks blue-green because of traces of methane in the atmosphere 0 It has a group of thin flat rings 0 Discovery of Uranus 0 Discovered in 1781 0 They first thought it was a comet, and later confirmed it was a planet

11. Uranus 0 Exploring Uranus 0 Voyager 2 arrived at Uranus and sent back close-ups of the planet. 0 Uranus’s axis of rotation is tilted at an angle of about 90 degrees from the vertical. It is rotating top to bottom instead of side to side, like other planets 0 Uranus’s Moons 0 Has at least 27 moons

12. Neptune 0 Neptune is a cold, blue planet, Its atmosphere contains visible clouds. 0 Discovery of Neptune 0 Was a result of <3 MATH!!! <3 0 They couldn’t see it, but used math and physics to figure out that there was another object out there. Later, someone actually found it!

13. Neptune 0 Exploring Neptune 0 Voyager 2 in 1989. 0 Like the red spot on Jupiter, there was a dark great spot on Neptune, but it went away. It was likely a storm. 0 Neptune’s Moons 0 There are at least 13 moons around Neptune. 0 Voyager Images show that the region near Triton’s South pole is covered by nitrogen ice.

14. Pluto 0 Pluto has a solid surface and is much smaller and denser than outer planets. Pluto is smaller than Earth’s moon. 0 Pluto has 3 known moons. 0 Pluto’s Orbit 0 It’s so far from the sun that it revolves around the sun only once every 248 Earth years

15. Pluto 0 What is a dwarf planet anyway? 0 Pluto used to be considered a planet, not a dwarf planet. Why the demotion? 0 There are many similar “planets” to these near Pluto also revolving the sun.