Camera. 30o 20o 340 o. 330 o. 40o. 320 o. 50 o. 310 o. 60 o. 300 o. 70 o. 290 o. 80 o. 280 o. East West. 90o. 270 o. 100 o. 110 o. 250 o. 120 o.

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1 130 o 120 o 110 o 100 o 150o 140 o 160 o 00 oo 350o 200 o 210 o 220 o 230 o East West 80 o 70 o 60 o 50 o 40o 30o 20o 10oo 340 o 240 o 280 o 290 o 300 o 310 o 320 o 330 o Lunar Phase Lab Materials: Lamp with no shade, table, 2 balls (preferably not shiny, like a tennis balls), dark location (indoor or outdoor), Moon Phase Angle Layout sheet and a camera. The camera can be digital or disposable. It MUST NOT FLASH. If your camera includes an automatic flash and you cannot turn it off, cover the flash with duct tape or layers of black paper so the light cannot get out. Otherwise, it will ruin the experiment. You will need about one roll of film for your camera. If you are buying film, get a high ASA number (400 and 800 are available generally.) The higher the number, the more sensitive the film and the less light the film needs to get a good exposure. You will be setting up a model of the Sun, Moon, and Earth. You will be photographing views of the Moon as it orbits the Earth and comparing the views from above the system to views as seen from the Earth You will use a lamp to represent the Sun and will record the light and shadowed parts of the Earth and Moon with the camera (the flash would ruin this). Except for your Sun, the rest of the area should be dark (outdoors at night is ok, or a dark room indoors) Use a high wattage light bulb, keep the bulb near the Moon, and use the most sensitive film or digital camera setting that you can, to ensure that the image will be properly exposed.. If you are using a camera that automatically adjusts for brightness, try not to let the light bulb be in the picture. When the actual light bulb is visible, it will fake the light meter into thinking the scene is brighter than it should be. The camera will adjust itself to taking a shorter exposure than it should and the picture will come out too faint. 1. Set up light so it shines at the same level as the balls (rather than from above or below) 2. Print the moon phase angle layout.. Lay it in on the table with zerodegrees toward the Sun. Light Bulb at table height Camera Ball, not shiny represents MOON Place 0o at Sun Move Moon Counterclockwise to Each Angle 3. Place the camera in the center of the moon phase angle layout, to represent the Earth 4. Move the Moon, and the azimuth circle to step the angles by 45 o at a time, as the Moon goes around the earth position going counterclockwise. Place the Moon at least 1.5 feet from the Astronomy 128 Lunar Phase Lab 1

2 130 o 120 o 110 o 100 o 150o 140 o 160 o 0 o 200 o 210 o 220 o 230 o East West 80 o 70 o 60 o 50 o 40o 30o 20o 10o 350 o 340 o 240 o 280 o 290 o 300 o 310 o 320 o 330 o camera, to allow the camera to focus. Be sure that you can see what part of the Moon is in light, and what part in shadow. If you cannot tell where the shadow starts, the camera will not be able to tell either. So if the shadow is not apparent, it may help to move the set up far away from any walls (so sunlight cannot be reflected and increase the overall light level). If you CAN tell where the shadow is, but it doesn t show up very well, you can stretch a colored rubber band around Moon ball and twist the ball until the rubber band lines along the shadow edge. Turn the camera to view the Moon each time, and take a photo. Record the frame number on the data sheet (exposure time, F# etc if application). 5. Put a ball in the center of the angle circle to represent the Earth, move the Moon around through the same angles again, and now photograph from above the scene. Be sure that you can see what part of the Moon is in light, and what part in shadow. Record the frame number on the data sheet, along with the camera set up (exposure time, F# etc if application). Light Bulb at table height Take Picture from Above Include Earth, Moon Ball for Earth Ball, not shiny represents MOON Place 0o at Sun Move Moon Counterclockwise to Each Angle 6. Get your pictures developed and printed (if they are digital pictures, print them). Smaller prints are better (and cheaper), If the pictures do not come out, REDO them. If the pictures are too dark to see anything, redo with a longer exposure, brighter light bulb, lighter color ball etc. If you pictures come out a little blurry, just use them. 7. Attach the pictures to your the Moon Phase layout picture, near the Moon position they correspond to. There will be two pictures near each Moon position, for a total of 16 pictures. Astronomy 128 Lunar Phase Lab 2

3 8. Match up the following names and descriptions of the Moon s appearance with the angle on the Moon Phase Angle Layout. Each of these descriptions refers to the Moon s appearance as seen from EARTH. Write the shape name on the phase picture at the correct position and on the photo data sheet. Full Moon appears entirely bright, the edge forms a complete circle. New Moon appears entirely dark from Earth. You will be able to see the Moon in your model, but in the real sky, the Moon is not normally noticeable in sky because it is in roughly the same direction as the Sun. Quarter Moon- Half of the Moon is bright, half dark as seen from Earth. The shape is like the letter D, filled in. Gibbous Moon- More than half of the side of the Moon facing Earth is bright. Crescent Moon- the bright part is a crescent shape. Less than half of the side of the Moon facing Earth is bright. The Moon NEVER has shapes like a quarter of a pie or like a cookie with a bite taken out. 9. As you can see, there are 8 positions of the Moon on your diagram, but fewer than 8 names. List the shapes that occur more than once, tell at what angles they occur. Shape Angles at Which it occurs 10. The Moon goes around the Earth in the counterclockwise direction as seen from above the Earth s north pole. It goes from lower to higher number as labeled on the phase angle layout. The zero is considered the starting point. 11. What Moon phase is at angle zero? 12. The fraction of the Moon that is bright changes gradually, night to night. It must get larger, then smaller over time. Getting larger is called Waxing, Getting smaller is called Waning. Label the positions on the Moon Phase Layout with either Waxing or Waning depending on whether the part of the Moon that is bright is getting larger or smaller. If the Moon is entirely bright it 13. The half-bright moon do not include the words waxing or waning in the name. Rather they are called first quarter and third quarter, because one occurs one quarter of the way through the cycle from nothing bright through all bright to nothing again. Label the pictures first quarter and third quarter respectively. At this point you should have the angle layout with 16 pictures attached and with name of the moon phase written near the appropriate angle. If you are having difficulty deciding where to put the names, consult with your friends or the textbook (look in the table of contents for ChaissonMacmillan). 14. The Moon takes days to go through all its phases and return to the same phase again. That is why we measure time in moonths". People wanted to use the Moon s phases to keep track of time. Unfortunately, days does not divide the solar year evenly. The Moon moves at a rate that is roughly constant. How long would it take for the Moon to move from new to first quarter? Astronomy 128 Lunar Phase Lab 3

4 15. Basically what causes the Moon to have phases? 16. Pretend you are above the system of Earth and Moon, as you were for the second set of photos. Does either Earth or Moon show varying phases? Do they show just ONE phase? What phase name(s) would you give to the appearance of Earth and Moon? If you are answering several phase names, make a table of the angle and the phase name of each body at each set up. 17. If you were on the Moon, would the Earth show phases? IF so, what phase does the Earth have for each of the angles on the Moon phase angle chart? 18. Turn in Moon phase angle chart, with photos attached and names of Moon phases written in. Objective and Conclusion Data table for photos Answers to all these questions Lunar Phase Photo Data Phase Angle 0 o 45 o 90 o 135 o 180 o 225 o 315 o Picture Number, Camera at Earth s Position Picture Number, Camera above North Pole Moon s Phase as Seen from Earth (this is a name) Astronomy 128 Lunar Phase Lab 4

5 Moon Phase Angle Layout To Sun 0o 45o 315o EARTH OR CAMERA GOES HERE 270o 225o 135o 180o Astronomy 128 Lunar Phase Lab 5