Sun-Earth-Moon System

4. the phase where the left half of the moon is lit
6. the season when the hemisphere is tilted toward the Sun
7. the time it takes for an object to rotate around its axis one time
12. the lunar phase when the entire face of the moon is lit up
15. the movement of an object around another object
16. the time it takes for an object to go around another object one time
18. a tide created when the Earth, Moon and Sun are in a perpendicular arrangement
19. the two times of the year when day and night are of equal length

1. a tide caused when the Earth, Moon and Sun are oriented in a straight line
2. the period during which the lit part of the moon is increasing
3. the thin curved shape of the moon
5. the period during which the lit part of the moon is decreasing
8. the movement of an object around its axis
9. the season when the hemisphere is tilted away from the Sun
10. the lunar shape that is more than half but not yet full
11. either of two times of the year when the axis is at its greatest tilt
13. the imaginary line connecting the north and south poles
14. the phase where the right half of the moon is lit
17. the path an object takes around another object
18. the phase where the moon is between the Earth and Sun, making it invisible