1. Moon Phases

2. Half of the Moon is always lit up by the sun
Half of the Moon is always lit up by the sun. As the Moon orbits the Earth, we see different parts of the lighted area.

3. The revolution of the Moon around the Earth makes the Moon look as if it is changing shape in the sky. 

4. This is caused by the different angles from which we see the lighted part of the Moon's surface.  These are called "phases" of the Moon. 

6. The Moon passes through four major shapes during a cycle that repeats itself every 29.5 days.  The phases always follow one another in the same order:
New moon
First quarter
Third quarter
Full moon

7. New Moon

8. First Quarter Moon

9. Third Quarter Moon

10. Full Moon

11. There are also four other phases of the Moon sometimes used.

12. ("Waxing" means increasing, or growing larger.)

13. Waxing Crescent Moon

14. Waxing Gibbous Moon

15. "Waning" means decreasing, or growing smaller.

16. Waning Gibbous Moon

17. Waning Crescent Moon

18. http://www. opencourse. info/astronomy/introduction/04

19. Waxing & Waning

22. Moon Movie
The movie is an animated GIF created by Antonio Cidadao from a sequence of still images taken during March and April 1998.
Copyright Antonio Cidadao.

23. MOON QUIZ!!