1. Week 5

2. lunar cycle the 28 day period in which the moon’s orbit around the Earth causes it to reflect the sun in different phases

3. crater a bowl-shaped structure at the top of a volcano or on a planet or moon

4. gravity the force that pulls objects toward each other

5. tilt to lean, tip, or slant to one side

6. axis an imaginary line that passes from the North Pole to the South Pole through Earth’s center

7. full moon the phase of the moon when the side turned toward the earth is entirely lit

8. half moon the phase of the moon when one half of the face turned toward the Earth is lit- can be either side depending on whether it is waxing or waning

9. quarter moon the phase of the moon when one quarter (one- fourth) of the face turned toward the Earth is lit

10. new moon the phase of the moon when the side turned toward the earth is entirely dark

11. rotation the spinning of a planet or moon on its axis

12. revolution one complete trip of a planet around the sun

13. orbit the path that one object in space takes around another object in space

14. waxing The moon at any time after new moon and before full moon, so called because its illuminated area is increasing

15. waning The moon at any time after full moon and before new moon, so called because its illuminated area is decreasing.

16. Slide 2: http://paganinstitute.org/images/Astronomy/lunar_orbit&phases.jpg Slide 3: http://laps.fri.uni-lj.si/~duke/HPpictures/crater.jpg Slide 4: http://www.adlerplanetarium.org/education/resources/gravity/img/gravity.jpg Slide 5: http://www.2012-online.net/images/AxialTilt_1.jpg Slide 6: http://www.chanceandchoice.com/ChanceandChoice/earthinclined.jpg Slide 7: http://www.cs.princeton.edu/~jhalderm/pics/pu0001/m/full_moon.jpg Slide 8: http://www.northrup.org/Photos/moon/low/half-moon.jpg Slide 9: http://quartermoonbows.com/Photos/trimquartermoon.JPG Slide 10: http://www.siennasoft.com/stargazer/images/1557OldMoon-NewMoon.jpg Slide 11: http://www.hort.purdue.edu/newcrop/tropical/lecture_02/02m.jpg Slide 12: http://www.teslasociety.com/pictures/solar10.jpg Slide 13: http://cse.ssl.berkeley.edu/Segwayed/lessons/cometstale/images/orbit_med.gif Slide 14: http://www.globalsecurity.org/military/ops/images/Moon_waxcres.gifhttp://www.globalsecurity.org/military/ops/images/Moon_waxcres.gif Slide 15: http://www.globalsecurity.org/military/ops/images/Moon_wancres.gif