1. Moon and its motions

4. The Earth’s Moon
Surface features
Maria
Craters

6. Movements of the Moon Lunar rotation and revolution Go to ESRT page 15
Period of rotation = ______________
Period of revolution = ______________
Why do we always see the same side of the moon?
27.3 days
27.3 days
Period of rotation = period of revolution

7. To an observer on earth the moon rises and sets 50 min
To an observer on earth the moon rises and sets 50 min. later each night.
Why is there a difference in period of revolution and the moon cycle?

8. Notice in picture 1, the moon is directly between the Earth and the Sun. But by position 5, even though the moon is directly below the Earth, it is no longer between the Earth and Sun. The moon must travel 2.2 more days to be exactly between the Earth and Sun (new moon).

9. Time for moon to complete all phases in its cycle?
days

10. Apogee – farthest point in an orbit
Perigee – closet point in an orbit

11. Moon’s Revolution Moon’s orbit around the earth is
This causes the moon’s diameter/size to change in a
elliptical, with Earth at one of the foci
cyclic manner

12. Moon looks bigger at perigee, especially when it first rises

13. Which is at perigee? Which is at apogee?

14. Phases of the Moon - Reasons
Caused by
We see the illuminated part of the moon’s surface
CYCLIC
Moon’s revolution around Earth

15. Phases of the Moon

16. Only the half facing the sun will be illuminated.
Color the illuminated and dark half of each moon.

17. Next, draw the moon’s orbit around the earth

18. Purple line is the orbit of the moon around the Earth

19. What does the moon look like from Earth at Position #1?
NEW MOON

20. What does the moon look like from Earth at Position #2?
WAXING CRESCENT

21. What does the moon look like from Earth at Position #3?
FIRST QUARTER

22. What does the moon look like from Earth at Position #4?
WAXING GIBBOUS

23. What does the moon look like from Earth at Position #5?
FULL MOON

24. What does the moon look like from Earth at Position #6?
WANING GIBBOUS

25. What does the moon look like from Earth at Position #7?
THIRD QUARTER

26. What does the moon look like from Earth at Position #8?
WANING CRESCENT

27. Waxing and Waning Waxing – increase of moon’s visible light
- new moon to full moon
Waning – decrease of moon’s visible light
- full moon to new moon
Time is takes to go from full moon to the next full moon? ____________
29-30 days

29.
(mr lee rap)