I. MODELING THE PHASES OF THE MOON:

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1 Phases of the Moon INTRODUCTION: In this lab we will model the phases of the Moon and observe the Moon over a period of one month to observe the phases and the times of Moonrise and check for patterns. You will analyze your observations, compare them with accepted values, write up the results in a lab report format. Please include all observations as well as your map of the Moon. I. MODELING THE PHASES OF THE MOON: We will model the moon with a 2 ball (the size of a golf ball or ping-pong ball), and a bright light source (e.g. A lamp with the shade removed). The ball represents the Moon and the light represents the Sun. Your head represents the Earth - determine which direction it rotates (imagine that your left eye is Europe and your right eye is America which sees the Sun first?) Holding the ball in front of you, rotate in the direction you determined. The Moon orbits the Earth in the same direction the Earth rotates. Notice that the illumination of the ball goes through phases just like the Moon does. (See Figure 1). Rotate so the ball is illuminated the same as each of the eight phases listed below. For each phase estimate the time of moonrise based on the relative positions of the Moon and Sun. Figure 1. One half of the Moon is illuminated by the Sun (unless there s a Lunar Eclipse), however, the illuminated half is not always facing the Earth. The bottom row shows the view from Earth, the figure above shows the position of the Earth and Moon relative to the Sun s rays.

2 II. OBSERVING THE PHASES OF THE MOON During the next month or so you will observe the Moon on twelve different days (or nights). For each observation, you will record the date and time, the altitude of the Moon measured from either the East or West Horizon (whichever is closer to it), a drawing of the Moon, and its apparent phase. You will estimate the time of Moonrise from the position of the Moon in the sky. For each observation, draw a picture of the Moon, carefully shading to show how much of it is illuminated. Draw large craters and maria which you can see to aid in indicating how much of the Moon is illuminated: which maria are on the day side and which are on the night side. Find and label the lunar maria and craters on the included map of the Moon. For your assistance, a map of Lunar craters and maria can be found at: You can look up the times of moon rise at: HINT: If you look up the time of moonrise and observe the Moon a few hours after it will be much easier to measure the position of the Moon and to calculate your estimated time of moonrise. III. QUESTIONS TO ADDRESS IN YOUR LAB REPORT: Note: these questions are to be addressed in the lab write up, you do not have to include the question, if you discuss the topics thoroughly and address all of them. 1) Obtain the times of Moonrise for each day for this school term and plot them on a graph. Indicate the days of Full, New and Quarter moons on this graph. Mark the times of Moonrise determined by your observations. How well do they match? Can you explain any differences? 2) Does the time of moonrise vary with the phase? What time do the New Moons typically rise? What about Full Moons? Also, First and Third Quarter Moons. Are these exactly the same as what you expected based on the model of the phases of the Moon in Section I? Why or why not? 3) How much does the time of moonrise vary from one day to the next? Is it always the same amount (hint: check the shape of the moonrise plot) if not what are the minimum, maximum and average amounts? 4) Is there a Moonrise everyday? How do you explain this? (Hint: check around Third Quarter what happens then?) 5) Is the side of the Moon illuminated (e.g. East or West) the same for a First Quarter as a Third Quarter? Based on your model of Lunar Phases, does this make sense? Explain how you could determine if the Moon is waxing or waning based on this observation. 6) Explain how you could tell whether the Moon is First or Third Quarter based on the time of observation.

3 Identify the following features on the image of the Moon. For assistance, you may refer to the website 1 Mare Frigoris (Sea of Cold) 2 Mare Imbrium (Sea of Rains) 3 Sinus Aestuum (Bay of Seething) 4 Sinus Medii (Bay of the Center) 5 Mare Vaporum (Sea of Vapors) 6 Mare Serenitatis (Sea of Serenity) 7 Mare Tranquillitatis (Sea of Tranquillity) 8 Mare Crisium (Sea of Crises) 9 Mare Fecunditatis (Sea of Fecundity) 10 Mare Nectaris (Sea of Nectar) 11 Mare Nubium (Sea of Clouds) 12 Mare Humorum (Sea of Moisture) 13 Mare Cognitum (Known Sea) 14 Oceanus Procellarum (Ocean of Storms) 15 Sinus Roris (Bay of Dew) 16 Sinus Iridum (Bay of Rainbows) 17 Crater Tycho 18 Crater Copernicus 19 Crater Kepler 20 Crater Plato

4 Moon Observation Sheet (Please make copies: one for each observation) Date/Time of Observation Location: Dist of Moon from E / W (circle one) Horizon. Time of Moonrise and Lunar Phase based on Observation. Notes:

5 Moon Observation Sheet (Please make copies: one for each observation) Date/Time of Observation Location: Dist of Moon from E / W (circle one) Horizon. Time of Moonrise and Lunar Phase based on Observation. Notes: