Earth's Motion and Natural Phenomena

1. Chapter Introduction Lesson 1 Earth’s Motion Lesson 2 Earth’s Moon Lesson 3Eclipses and Tides Chapter Wrap-Up Jason Reed/Photodisc/Getty Images Chapter Menu

2. What natural phenomena do the motions of Earth and the Moon produce? Chapter Introduction

3. What do you think? Before you begin, decide if you agree or disagree with each of these statements. As you view this presentation, see if you change your mind about any of the statements. Chapter Introduction

4. 1. Earth’s movement around the Sun causes sunrises and sunsets. 2. Earth has seasons because its distance from the Sun changes throughout the year. 3. The Moon was once a planet that orbited the Sun between Earth and Mars. Do you agree or disagree? Chapter Introduction

5. 4. Earth’s shadow causes the changing appearance of the Moon. 5. A solar eclipse happens when Earth moves between the Moon and the Sun. 6. The gravitational pull of the Moon and the Sun on Earth’s oceans causes tides. Do you agree or disagree? Chapter Introduction

6. Earth’s Motion • How does Earth move? • Why is Earth warmer at the equator and colder at the poles? • Why do the seasons change as Earth moves around the Sun? Lesson 1 Reading Guide - KC

7. Earth’s Motion • orbit • revolution • rotation • rotation axis • solstice • equinox Lesson 1 Reading Guide - Vocab

8. Earth and the Sun • The nearest star to Earth is the Sun. • The Sun is approximately 150 million km from Earth. Lesson 1-1

9. Earth and the Sun(cont.) Earth moves around the Sun in a nearly circular path. Lesson 1-1

10. Earth and the Sun(cont.) • The path an object follows as it moves around another object is an orbit. • The motion of one object around another object is called revolution. • Earth makes one complete revolution around the Sun every 365.24 days. Lesson 1-1

11. Earth and the Sun(cont.) What produces Earth’s revolution around the Sun? Lesson 1-1

12. Earth and the Sun(cont.) Earth orbits the Sun because the Sun’s gravity pulls on the Earth. Lesson 1-1

13. Earth and the Sun(cont.) • A spinning motion is called rotation. • The line on which an object rotates is the rotation axis. • The tilt of Earth’s rotation axis is always in the same direction by the same amount. • During half of Earth’s orbit, the north end of the rotation axis is toward the Sun and during the other half the north end of the rotation axis is away from the Sun. Lesson 1-1

14. Temperature and Latitude Because Earth’s surface is curved, different parts of Earth’s surface receive different amounts of the Sun’s energy. Lesson 1-2

15. Temperature and Latitude(cont.) Relative to the direction of a beam of sunlight, Earth’s surface tends to become more tilted as you move away from the equator. Why is Earth warmer at the equator and colder at the poles? Lesson 1-2

16. Temperature and Latitude(cont.) The energy in a beam of sunlight tends to become more spread out the farther you travel from the equator Lesson 1-2

17. Temperature and Latitude(cont.) Regions near the poles receive less energy than regions near the equator, which means Earth is colder at the poles and warmer at the equator. Lesson 1-2

18. Seasons During one half of Earth’s orbit, the north end of the rotation axis is toward the Sun. Lesson 1-3

19. Seasons(cont.) • Due to Earth’s tilt, the northern hemisphere receives more solar energy. • Temperatures increase in the northern hemisphere and decrease in the southern hemisphere. • This is when spring and summer happen in the northern hemisphere, and fall and winter happen in the southern hemisphere. Lesson 1-3

20. During the other half of Earth’s orbit, the north end of the rotation axis is away from the Sun. Lesson 1-3

21. Seasons(cont.) • Due to Earth’s tilt, the southern hemisphere receives more solar energy. • Temperatures decrease in the northern hemisphere and increase in the southern hemisphere. • This is when fall and winter happen in the northern hemisphere, and spring and summer happen in the southern hemisphere. Lesson 1-3

22. Seasons(cont.) How does the tilt of Earth’s rotation axis affect Earth’s weather? Lesson 1-3

23. Seasons(cont.) There are four days each year when the direction of Earth’s rotation axis is special relative to the Sun. Lesson 1-3

24. Seasons(cont.) A solsticeis a day when Earth’s rotation axis is the most toward or away from the Sun. Lesson 1-3

25. Seasons(cont.) An equinoxis a day when Earth’s rotation axis is leaning along Earth’s orbit, neither toward nor away from the Sun. Lesson 1-3

26. Seasons(cont.) equinox from Latin equinoxium, means “equality of night and day” Lesson 1-3

27. Seasons(cont.) The Sun’s apparent path through the sky in the northern hemisphere is lowest on the December solstice and highest on the June solstice. Lesson 1-3

28. The gravitational pull of the Sun causes Earth to revolve around the Sun in a near-circular orbit. Lesson 1 - VS

29. Earth’s rotation axis is tilted and always points in the same direction in space. Lesson 1 - VS

30. Equinoxes and solstices are days when the direction of Earth’s rotation axis relative to the Sun is special. Lesson 1 - VS

31. Which body’s gravitational pull causes the Earth to orbit the Sun? A. Earth B. Sun C. Moon D. none of these Lesson 1 – LR1

32. Relative to the direction of a beam of sunlight, what happens to Earth’s surface as you move away from the equator? A. The surface becomes less tilted. B. The surface becomes flat. C. The surface becomes more tilted. D. There is no change in the relationship. Lesson 1 – LR2

33. Which term refers to the motion of one object around another object? A. orbit B. rotation C. rotation axis D. revolution Lesson 1 – LR3

34. 1. Earth’s movement around the Sun causes sunrises and sunsets. 2. Earth has seasons because its distance from the Sun changes throughout the year. Do you agree or disagree? Lesson 1 - Now

35. Earth’s Moon • How does the Moon move around Earth? • Why does the Moon’s appearance change? Lesson 2 Reading Guide - KC

36. Earth’s Moon • maria • phase • waxing phase • waning phase Lesson 2 Reading Guide - Vocab

37. Seeing the Moon You only see the Moon because light from the Sun reflects off the Moon and into your eyes. Lesson 2-1

38. The Moon’s Formation According to the giant impact hypothesis, shortly after Earth formed about 4.6 billion years ago, an object about the size of the planet Mars collided with Earth. Lesson 2-2

39. The Moon’s Formation(cont.) The impact ejected vaporized rock that formed a ring around Earth. Lesson 2-2

40. The Moon’s Formation(cont.) Eventually, the material in the ring cooled and clumped together and formed the Moon. Lesson 2-2

41. The Moon’s Formation(cont.) • The surface of the Moon was shaped early in its history. • Moon’s craters were formed when objects from space crashed into the Moon. Lesson 2-2

42. The Moon’s Formation(cont.) The large, dark, flat areas on the Moon are calledmaria. maria from Latin mare, means “sea” Lesson 2-2

43. The Moon’s Formation(cont.) • When the maria formed, lava flowed up through the Moon’s crust and solidified, covering many of the Moon’s craters and other features. • The light-colored highlands are too high for the lava that formed the maria to reach. Lesson 2-2

44. The Moon’s Motion • The Moon rotates as it revolves around Earth. • One complete rotation of the Moon takes 27.3 days, meaning the Moon makes one rotation in the same amount of time that it makes one revolution around Earth. Lesson 2-3

45. The Moon’s Motion (cont.) What produces the Moon’s revolution around Earth? Lesson 2-3

46. The Moon’s Motion(cont.) • Because the Moon takes the same amount of time to orbit Earth and make one rotation, the same side of the Moon is always facing Earth. • This side of the Moon is called the near side. • The side of the Moon that cannot be see from Earth is called the far side of the moon. Lesson 2-3

47. The Moon’s Motion(cont.) Lesson 2-3

48. Phases of the Moon The lit part of the Moon or a planet that can be seen from Earth is called a phase. phase Science Use how the Moon or a planet is lit as seen from earth Common Use a part of something or a stage of development Lesson 2-4

49. The motion of the Moon around Earth causes the phase of the Moon to change. Jason Reed/Photodisc/Getty Images Lesson 2-4

50. Lesson 2-4