# Sun- Earth-Moon-System Model

By Laura Hospitál on Jan 31, 2015

This interactive model allows the student to manipulate the position of the Moon as it revolves around the Earth in order to understand the relative positions of the Sun, Earth, and Moon during the phases of the Moon.

This model was built by Jim Clark, science teacher at TSBVI.

Pictures by Ditmar Hospitál

## Preparation:

Please begin preparation by viewing the picture.
1. Cut out a 3" diameter circle of the red sponge for the Sun.
2. Cut out a 1" diameter circle from the blue sponge for the Earth.
3. Tack down the Sun with a small nail to the middle of one of the shorter sides of the graph board.
4. Cut a piece of white string 12 " long and a piece of red rope or yarn 9" long.
5. Tie the white string into a loop.
6. Loop the white string underneath the blue tack and  attach the blue tack to the middle of the graph board by putting it through the small blue piece of sponge and the red yarn.  See picture
7. Loop the second end of the white string under the round pin and tape it in place.  This pin will represent the Moon.
8. The other end of the red yarn will be attached with a red tack 1 " from the Sun and the yarn will be tucked under the sponge to hold it in place.
9. Place alternating red push pins and differently shaped pins every 45 degrees around the Earth.  These will represent the placement of the Moon at the various Moon phases.

## Materials

Note: Both Amazon.com and alibaba.com have a variety of push pins for sale as do Office Depot and Office Max
• APH Graphic Aid for Mathematics
• 4 push pins of the same color (blue push pins in the picture)
• 1 push pin of a different color (white push pin in the picture)
• 4 push pins with a different shape (black pins in the picture)
• 1 push pin (preferable round ) to represent the Moon
• A red sponge - to represent the Sun
• A blue sponge- to represent the Earth
• Red yarn or rope
• White string

## Procedure

1. Begin by describing the board and guiding students to tactually observe the following: a. The location of the Sun (large sponge), Moon (round tack), and the Earth (small sponge). b. Markers - Each tack represents the location of a phase of the Moon as the Moon revolves around the Earth.  The thumb tacks represent First Quarter, Full Moon, and 3rd Quarter while the other tacks represent Waxing Crescent, Waxing Gibbous, Waning Gibbous, and Waning Crescent      c. Describe the red yarn as representing the Sun's rays and have students tactually observe it.  d. Describe the white string that connects the Earth and the Moon.  Explain that there is not a string connecting the Earth and Moon but that this string describes the path of the Moon around the Earth.     2. Quickly say that the only thumb tack that moves is the Moon in this model. You may wish to clarify that the Earth is also moving but that this model does not show this motion.   3. Begin with the Moon in the Full Moon position (See picture at top). In this position, the Earth is between the Sun and the Moon. Describe the view from the Earth as a complete Moon and the position of the Moon, Earth, and Sun at this phase.   4. Before using the model to show students the phases in order, bring the Moon back to the Sun (New Moon). Ask the student if he can feel the Sun's rays (red string) Explain that in this position (New Moon) the Moon is not visible at all because the Sun's rays are hitting the back of the Moon.     5. Proceed to utilize the model to teach the students the positions of the Moon relative to the Earth and Sun during each phase by rotating the Moon around the Earth to the right (counterclockwise) Phases in order: New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, Waning Crescent, and then returning to New Moon.   6.  Assessment of students understanding of the phases of the Moon can be part of an informal or formal assessment using the board.

Model of Phases of the Moon

## Variations

Students who need an extra challenge can be asked to measure the angles between the Sun, the Earth and the Moon at various phases using the APH Adapted Protactor.

## NGSS Standards:

Middle School - Space Systems

ESS1.A: The Universe and Its Stars- Patterns of the apparent motion of the sun, the moon, and stars in the sky can be observed, described, predicted, and explained  with models. (MS-ESS1-1)