1. Lecture 11 Moon Phases and Eclipses Full Moon near Saturn The Moon will be full on Sunday, 4/17/11 so on Saturday and Sunday night it will be near Saturn, which reached opposition last week and, like the full Moon, is on the opposite side of the sky as the Sun.

2. In each phase of the Moon, how much of the Moon is lit up by the Sun? Half the Moon is always lit by the Sun Except...

3. When the Earth’s shadow hits the Moon we have a ……. Lunar Eclipse

4. Eclipses occur ONLY when the Moon crosses the plane of Earth’s orbit around the Sun AND ONLY during the NEW or FULL phases

5. Lunar Eclipse When Earth blocks most of the sunlight from illuminating the Moons surface for several hours when in the full moon phase

6. When the Moon’s shadow hits the Earth, we have a …. Solar Eclipse

7. Annular Eclipse Partial Eclipse Total Eclipse

8. Eclipses occur ONLY when the Moon crosses the plane of Earth’s orbit around the Sun AND ONLY during the NEW or FULL phases

9. Which positions cause which eclipses When the ______ is in the _____ phase and is directly in line with the _____ and the ____, you get a ______ eclipse? Moonfull EarthSun Moon Earth Sun new lunar solar

10. When the full Moon is rising in the East, what is the Sun always doing? The Sun is always setting in the West. Therefore the Sun and Moon are exactly ________ degrees apart…try a human animation if you are having difficulty visualizing this. The only exception is … 180 …if there is a lunar eclipse, with the Moon crossing the line of nodes.

11. How are the motions and positions of Earth and the Sun connected to what happens on Earth? Earth’s rotation on its axis determines the length of the day. Earth’s orbit around the Sun determines the length of the year. The tilt of Earth’s rotational axis with respect to the plane of Earth’s orbit causes the seasons.

12. The changing phases of the Moon originally inspired the concept of the month

13. Watch Movie at: http://antwrp.gsfc.nasa.gov/apod/image/9911/lunation_ajc.gif

14. Moon Phase Names New Moon Waxing Crescent First Quarter Waxing Gibbous Full Moon Waning Gibbous Third Quarter Waning Crescent

15. The Causes of Moon Phases Think to yourself about the answer to this question: What causes the phases of the Moon? Take out a piece of paper and quickly write out a brief answer.

16. How long does it take to complete the full cycle of Moon Phases? A. About a day B. About a week C. About a month D. About a year E. None of the above Check your answer with your partner!

17. Solar Period vs. Sidereal Period of the Moon

18. Synodic (Solar) vs. Sidereal Period of the Moon Synodic Period is 29.53 days, Moon rotates to the orange line, more than 360 degrees; back to the same phase (new moon) as leftmost image. Sidereal Period is 27.32 days, Moon rotates to the purple line (which should be parallel to the leftmost red dotted line), 360 degrees; not back to New Moon - same phase as leftmost image

19. Right now our Moon is just…

20. What phase is our Moon in right now? Just a day past First Quarter Discuss light fills in from the right-ish side. http://www.clarkplanetarium.org/pages/nightSky http://meteorshowersonline.com/lyrids.html http://yasirlioneljordan.blogspot.com/2011/04/moon-phases- 2011-february.html Lunar Calendar

22. Let’s Watch some Moon Phase Animations! Pay attention to where the Moon, Sun and Earth are located and how the Moon appears from Earth at each of these positions. Look at how much of the Moon is illuminated when at each position. Look at which side of the Moon is illuminated when at each position.

23. Animation ZOOM IN Prepare for Human Animation! Get volunteers! Look at tidal locking. Discuss plane of Moon’s orbit and angle. http://www.sumanasinc.com/webcontent/animations/content/ moonphase.html

24. What is a monthly cycle & what is a daily cycle? Label the daily times and how the Moon phases are broken up over time. Name the phases of the Moon that are shown. Discuss rising and setting.

25. Although the Moon is always ½ lit by the Sun, we see different amounts of the lit portion from Earth depending on where the Moon is located in its month-long orbit.

26. 1) How many phases shown in the picture will the Moon go through in one day? 2) How long does it take the Moon to complete one orbit? How many of the phases will the Moon have gone through in this time? 3) How long does it take the Earth to complete one rotation? How far will the Moon have moved? 4) How much of the Moons total surface is illuminated when it is in the New Phase? Full Phase? 5) How much of the illuminated surface of the Moon is visible from Earth when it is in the First Quarter Phase, Full Phase? 6) What time is it when the Waxing Gibbous Phase is highest in the sky, Rising? Setting? What phase will it be in one week later….see next slide for answer. SKIP RED PORTION.

27. A Moon Phase is highest in the sky at 9 pm today. What phase will the Moon have in three weeks after today?

28. Lecture Tutorial: Cause Moon Phases Work with a partner! Read the instructions and questions carefully. Discuss the concepts and your answers with one another. Take time to understand it now!!!! Come to a consensus answer you both agree on. If you get stuck or are not sure of your answer, ask another group. If you get really stuck or don’t understand what the Lecture Tutorial is asking, ask one of us for help.

30. A few more resources you might enjoy! Animations: more complex demo. http://jove.geol.niu.edu/faculty/stoddard/JAVA/moonphase.html http://jove.geol.niu.edu/faculty/stoddard/JAVA/moonphase.html Useful information and tables as covered in class: http://home.hiwaay.net/~krcool/Astro/moon/moonphase/ Gives information on the different moon phases and the times of day when they are visible.