I designed this as a way to visualize the Earth-Moon-Sun system each day through the lunar month. It shows the system from two perspectives. One is from an observer standing on earth. It shows where the moon and sun are in the sky relative to each other. The other perspective is from an observer in space, far enough away to see the north poles of the earth, sun, and moon. This perspective shows the angle between the three each day of the lunar month.
The image above Illustrates this. The green represents the earth and the horizon. The sun and moon discs are set for day 10 1/4 of the lunar month. This perspective shows that the moon is trailing the sun in the sky by more than 90 degrees and where it would be in the sky at sunset. If you ignore the green, then you are in space looking down at the north poles of the earth, moon, and sun on the same day. This shows the angle between the three, and the picture of the moon in the cutout of the moon disc shows the phase of the moon.
- 1-Manila folder for the background and horizon
- Poster board, cardboard, etc. to attach the sun and moon discs to make it more sturdy. A cereal box works great!
- Print out of the sun and moon discs
- 1 brad to attach the pieces and allow the sun and moon discs to rotate
- Liquid glue (glue sticks don't hold well enough) or rubber cement
Optional: Clear piece of plastic for the front so you can see through the "ground" when looking at the system from the space perspective.
Step 1: Prepare the Sun and Moon Discs
- Print one of each of the attached sun and moon discs.
- ***Ask an adult for help***** Cut them out along the outside lines.
- Cut a square piece of sturdy material a little larger than each disc.
- Use a piece of extra cardboard to spread a THIN layer of glue on a piece of your sturdy material squares. Make sure to cover it almost to the edges.
- IMPORTANT--If there are puddles of glue left after spreading it, use an extra piece of cardboard to scoop it off and throw away.
- Carefully place the disc on the glue and use your hands to gently smooth from the center toward the edges.
- Keep one hand pressing down at the center and slide the other had toward the top.
- Then do the same thing toward the bottom.
- Try to get all of the wrinkles out.
Step 2: Prepare the Background
- Cut the manila folder in half along the fold.
- Measure 4 1/2" (11.5 cm) up from the bottom on each side and mark it.
- Fold the bottom up at the marks. This is the "ground" and the top edge is the horizon line.
- On the left side, write the words "East" and below it "Rise".
- On the right side, write the words "West" and below it "Set".
- In the middle, about 2" (5 cm) down, write the word "South".
This shows the directions you would look and where the sun and moon rise and set.
Step 3: Complete Sun and Moon Discs
When the glue dries on the sun and moon discs, it is time too cut them out again.
- ******Ask an adult for help****** Cut the sun and moon discs out along the outside edge of each disc.
- If any of the edge is not attached, add a tiny drop of glue under the paper and smooth it down. Then let it dry.
- ******Ask an adult for help****** Use scissors to poke a hole through the black dot in the center of each disc. NOTE: The dot in the center of the moon disc is on the earth picture.
Step 4: Assembly
- Place the sun disc on the background (manila folder) and use it to find the center of the background along the horizon line (top edge of fold). You could also measure the width of the background and divide by 2. Mine was 8 3/4" wide (22.2 cm). So I marked it 4 3/8" (11.1 cm).
- ******Ask an adult for help****** Use scissors to poke a hole in the background piece at the mark, but just above the horizon line.
- Put the sun disc on the background with the fold over the bottom half.
- Put the moon disc on top of the sun disc. Line up the holes of the discs and the background.
- From the front, push the brad through the holes and fold over the flanges on the back. (I had to use a screw because I lost my brad.)
- Put a thin line of glue along the side edges of the flap. I drew a squiggly line in the picture to show where. It works best to squeeze gently then use the tip of the glue bottle to smear the drop around. Make sure that none of the glue goes under the sun disc.
- Fold the flap up and lay something heavy on the edges to hold them while they dry.
Step 5: How to Use Your Lunasphere
The Lunasphere can be used to find where the moon will be in the sky on a specific day of the lunar month, or it can be used to explore the sun-earth-moon system.
To Find the Moon on a Specific Day of the Lunar Month
- Go to a website that has a lunar calendar like “The Old Farmers Almanac” (https://www.almanac.com/astronomy/moon/calendar# )
- Find the last new moon before the current date.
- Count the number of days from the previous new moon to the current date.
- Turn the sun disc until the number of days from the last new moon is lined up with the notch on the moon disc.
- Hold the background with one hand along the edge. With the other hand hold the sun and moon discs together so the current lunar day stays lined up with the notch and turn it clockwise.
- Eventually, you will see the sun rise on the left side of the background, go across the sky, and then set on the right side. You will also see the moon move across the sky from east to west. This shows where it is in relation to the sun on that day.
Using the Lunasphere to Explore the Sun-Earth-Moon System
- When looking from the space perspective, the moon revolves around the earth counter clockwise. Notice the arrow on the moon disc pointing to the left. Each day the moon moves a little over 12° farther towards the east.
- When looking at it from the ground perspective, the sun and moon appear to move from left to right, or clockwise, across the sky. Notice the arrow on the sun disc pointing to the right. Hold the sun and moon discs together and turn them clockwise to simulate their motion across the sky each day.
- You'll understand the system when you can discover the answer to these questions:
- What part of the lunar month does the moon follow the sun across the sky?
- What part of the lunar month does the moon precede the sun across the sky?
- What is the only day of the lunar month can a lunar eclipse happen (Earth's shadow darkens the moon)?
- What is the only day of the lunar month that a solar eclipse can happen? (Moon blocks all or part of the sun from view)
Step 6: Answers
- Between new moon and full moon.
- Between full moon and new moon.
- Full moon when the order is sun-earth-moon.
- New moon when the order is sun-moon-earth.
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