1. THE SUN-MOON-EARTH SYSTEM
CHAPTER 2 LESSON 1
THE SUN-MOON-EARTH SYSTEM

2. I. INTRODUCTION
Why is the sun shaped like this?

3. I. INTRODUCTION
Where is the Earth located in this picture?

4. I. INTRODUCTION
Where is the moon located in this picture?

5. I. INTRODUCTION
What is this event called?

6. A. EARTH & THE UNIVERSE

7. A. EARTH & THE UNIVERSE
Earth is one of eight planets orbiting the Sun in our solar system.

9. The Sun is one of billions of stars in the Milky Way,
A. EARTH & THE UNIVERSE
The Sun is one of billions of stars in the Milky Way,

10. which is one of billions of galaxies in the universe.
A. EARTH & THE UNIVERSE
which is one of billions of galaxies in the universe.

11. EARTH & THE UNIVERSE

12. A. EARTH & THE UNIVERSE
Objects in our solar system orbit the Sun due to the Sun’s huge mass and gravitational pull.

13. A. EARTH & THE UNIVERSE

14. B. MOTIONS OF EARTH
Although we don’t sense its motion, Earth is moving rapidly through space. 67,000 mph

15. REVOLUTION
the orbit of an object around another object.

17. REVOLUTION Earth orbits the Sun once every 365.25 days.
We call this one year.

18. REVOLUTION
What happens with the 1/4th day of each year?

19. ASTRONIMAL UNIT (AU)
The average distance between Earth and the Sun is about 150 million km.

20. ASTRONOMICAL UNIT
The average distance between Earth and the Sun is about 150 million km.

21. ASTRONIMICAL UNIT

22. ROTATION
The spin of an object around its own axis.

24. ROTATION This motion causes day and night.
For Earth, a full rotation takes 24 hours

26. MOTIONS OF EARTH

27. C. EARTH’S TILT - SEASONS

28. C. EARTH’S TILT - SEASONS

29. EARTH’S TILT - SEASONS
The cause of seasons on Earth is related to the tilt of Earth’s axis toward or away from the Sun.

30. EARTH’S TILT - SEASONS

31. NG: EQUINOX

32. EQUINOX
On two days during the year, Earth’s axis does not tilt toward or away from the Sun.

33. EQUINOX
One at the beginning of the spring and the other at the beginning of the fall.

34. NG: SOLSTICE

35. SOLSTICE
On two days during the year, Earth’s axis tilts the most toward or away from the Sun.

36. SOLSTICE
One at the beginning of summer and one at the beginning of winter.

37. EQUINOX - SOLSTICE

38. EARTH’S TILT - SEASONS

39. NG: EARTH’S MOON

40. EARTH’S MOON
The Moon orbits Earth for the same reason that Earth orbits the Sun …

41. EARTH’S MOON
… The reason is the force of gravity.

42. FORMING OF MOON

43. EARTH’S MOON
A collision between Earth and another planet-sized object might have thrown a large amount of debris into orbit around Earth.

44. EARTH’S MOON Gravity pulled together the debris into a clump/disc.
The clump starts to spin due to gravity, shaping it into a sphere.

45. EARTH’S MOON Forming the Moon.
Gravity pulls the moon around the Earth.

47. EARTH’S MOON
The Moon rotates on its axis every 27.3 days.

48. EARTH’S MOON
The moon revolves around Earth in 27.3 days.

49. EARTH’S MOON
As the Moon orbits Earth, the visible part of the Moon reflecting the Sun’s light seems to change shape

50. EARTH’S MOON
These shapes are called the phases of the Moon.

51. EARTH’S MOON The moon move INTO the sunlight …
Then it moves out of the sunlight.

52. H: MOON’S PHASES

53. AN: MOON PHASES

55. EARTH’S MOON
NEW MOON - When the Moon is between Earth and the Sun, the half of the Moon facing Earth is in darkness.

56. EARTH’S MOON
Over the next two weeks, we say that the Moon is waxing.

57. EARTH’S MOON
WAXING = GETTING BIGGER.

58. EARTH’S MOON
When Earth is between the Moon and the Sun, the half of the Moon facing Earth is completely lit up.

59. EARTH’S MOON
Over the next two weeks, we say that the Moon is waning.

60. EARTH’S MOON
WANING = DISAPPEARING

61. D. EARTH’S MOON
DEMONSTRATION: MOON PHASES

62. D. EARTH’S MOON
VIDEO: PHASES OF THE MOON

65. TIDES
The daily rising and falling levels of the oceans and other large bodies of water ...

66. TIDES
… which are caused by the gravitational pull of the Moon and the Sun.

68. NTG: TIDES

69. HIGH TIDES
A bulge of water forms at the two places on Earth that are closest to and farthest from the Moon, and these places have high tides.

70. SUN & TIDES
The location of the Sun relative to the Moon can cause an increase or decrease in the level of the tides.

71. SPRING & NEAP TIDES

72. REVIEW: TIDES

73. ECLIPSES
Movement of one solar system object into the shadow of another solar system object.

74. SOLAR ECLIPSE

75. SOLAR ECLIPSE
People in the Moon’s shadow on Earth see the Moon partially or completely cover the Sun.

76. SOLAR ECLIPSE
The moon is in between the sun and Earth.

77. NG: LUNAR ECLIPSE

78. LUNAR ECLIPSE
People on Earth see Earth’s shadow partially or completely cover the moon.

79. LUNAR ECLIPSE
Earth is between the Sun and moon.

80. SOLAR ECLIPSE

81. LUNAR ECLIPSE

82. REVIEW: ECLIPSES