Earth, Moon, Sun

1. light-colored, mountainous, heavily cratered areas of the Moon.
4. depression on the lunar surface formed from space material impact.
6. occurs when the Moon passes between Earth and the Sun and the Moon casts a shadow on Earth, blocking Earth's view of the sun.
9. dark-colored, smooth plain on the Moon.
11. layer of loose, ground-up rock on the lunar surface.
12. farthest point in the Moon's orbit around Earth.
15. closest point in the Moon's orbit around Earth.
16. when Earth passes between the Sun and the Moon, and the Earth's shadow falls on the Moon.
17. first day of winter; usually occurs on December 21st.

2. First day of fall; usually Sept. 21st
3. the moon orbits the Earth in the same amount of time as it takes the Moon to spin once on its axis.
5. plane that contains Earth's orbit around the Sun.
7. first day of summer; usually occurs on June 21.
8. First day of Spring; usually occurs on March 21st.
10. amount of sunlight that is reflected by a surface
13. mate rial that falls back to the lunar surface after being blasted out by the impact of a space object.
14. alley-like structure that meanders across some of the Moon's maria; resembles dry riverbeds
18. long trail of ejecta that radiates outward from a crater.