1. Chapter 21 Sections 1-3 Review PowerPoint

2. Know the order in which the planets orbit the Sun: Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune

3. Know the 4 Terrestrial/Inner Planets: Mercury Venus Earth Mars They are terrestrial planets because they resemble Earth. (Very dense and rocky)

4. The Inner planets are different from the outer planets because: Smaller Spaced more closely together Dense and rocky Closer to the Sun

5. Know the Gas Giants/Outer Planets: Jupiter Saturn Uranus Neptune

6. Gas Giants are different from the Terrestrial planets because: Very large Made Mostly of gases Spaced farther apart Farther from the Sun

7. Mercury Terrestrial planet Closest planet to the Sun Smallest planet Period of Rotation (day) is almost 2 Earth months long Period of Revolution (year) is 88 Earth days Prograde rotation

8. Venus Terrestrial planet Hottest planet Densest atmosphere-mostly made of carbon dioxide Greenhouse effect causes high temperatures Retrograde rotation Similar to Earth with size, mass, and density

9. Earth Terrestrial planet Prograde rotation Only planet with liquid water (life)

10. Mars Terrestrial planet Prograde rotation Contains polar ice caps Largest mountain in solar system (Olympus Mons) Dry riverbeds (possible warmer climate)

11. Jupiter Gas giant Prograde rotation Largest planet As you go deeper into the atmosphere, hydrogen gas changes to liquid hydrogen, then becomes a liquid, metallic state Great Red Spot-storm system in atmosphere

12. Saturn Gas giant Prograde rotation Known for its ring system Still forming from hydrogen sinking to core and giving off extra energy Fastest winds in the solar system (1,700 km/h)

13. Uranus Gas giant Retrograde rotation Axis of rotation is tilted nearly 90 degrees and lies nearly flat to the plane of its orbit

14. Neptune Gas giant Prograde rotation Storm system called the Great Dark Spot

15. Pluto Dwarf planet Rocky, dense surface

16. Know the terms: Period of rotation Period of revolution Prograde rotation Retrograde rotation Terrestrial planet Gas Giant

17. Astronomical Unit 8.3 light minutes 150,000,000 km Equals the distance from the Sun to the Earth Used to measure distances in our solar system

18. Light can travel: 300,000 km/s 18,000,000 km/ min