Moon Phases and Tides
[related Video]

Students will be able to investigate the earth, moon, and sun as a system and explain how the motion of these bodies results in the phases of the moon and eclipses. They will answer the research question: "Why does the high-tide level of the Passaic River at the Belleville Bridge change throughout the month?"

In a moon diary which was generated using a calendar program, students record the daily appearance of the moon for a month, along with the high-tide data for the selected area. Any river or location can be used for this project. We selected the Belleville Bridge since it has a tide gauge and is in Bergen County. The Passaic River is a tidal river that flows into the Newark Bay in New Jersey. Tides were recorded on each calendar day for the Belleville Bridge area on the Passaic River go to( http://tbone.biol.sc.edu/tide/ ) select U.S. Upper East Coast (Maine through Virginia), and search for an appropriate NJ region, using the Edit/Find button). Additional tide data at near real time is also at NOAA http://tidesonline.nos.noaa.gov (select the state, and then the nearest region). Moon phases can be found at http://www.google.com/moon/. Descriptions of phases by date and year are at http://aa.usno.navy.mil/data/docs/MoonPhase.html

Project Data
Students will use high-tide data to generate a line graph of tide vs. time. They then will sketch the new moon, first quarter, full moon, and fourth quarter onto this graph. On a separate sheet of paper, students explain their observations and sketch the relative positions of the moon, sun, and earth throughout the month based on a simulation done in class.

Procedure

1. Ask students to describe what they've observed about the phases of the moon.
   
2. Distribute worksheets (sun-earth-moon relationships: moon phases worksheet). While students complete the observation and speculation portion of the worksheet, set up lamp in the center of the room.
3. Distribute styrofoam balls. Explain that students will be standing in a circle around the room. The lamp will be the sun. The students' heads will be the earth. The styrofoam ball will be the moon.
4. Have students form a circle facing into the center of the room. They should hold the styrofoam ball on the dowel between their eyes and the lamp. This is the new moon phase. Students should slowly turn to the left stopping at the first quarter, full moon, and final quarter. At each stop ask students to describe what they see. Ask why a quarter of the surface is reflecting, why half the sphere is reflecting, and why sometimes none of the surface is reflecting back to the earth.
5. Have students complete the drawings. Collect styrofoam balls.
6. PowerPoint notes to verify sketches.

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Moon Phase and Tide Project

The Research Question: Why does the high-tide level of the Passaic River change daily?

Step 1. Observation
A. Moon Phases
Each night or morning, if necessary, record the appearance of the moon by sketching it onto the moon diary for April 2002. If the sky is overcast, write that on the diary.

B. High-Tide Data
Record the highest tide level for each day. High-tide data can be found in the newspaper, or find the high-tide data at the Belleville Bridge by using Internet links.

Step 2. Analyzing the Data
A. High-Tide Data
Create a line graph of high-tide versus time. The y-axis should be labeled in feet. The x-axis should be labeled by day of the month. Since time is continuous, the tide should be shown as a line graph.

B. Moon Phases
Over each peak or trough on the line graph, draw the phase of the moon for that day.

Step 3. The Explanation
Why does the high-tide level of the Passaic River change daily? Use your observations to answer this question. Draw a picture showing the location of the moon relative to the earth and sun for each phase. (Hint: The gravity of the situation will be apparent in your sketch.) See the section Final Report for what must be included.

Your Final Report

1. Title - Why Does the High-Tide Level of the Passaic River Change Each Day?
2. Written Report
   Paragraph 1 - Background information about the tidal characteristics of the Passaic River and it's geographic location.
   Paragraph 2 - Describe what you observed about the changing phases of the moon. Reference the moon diary.
   Paragraph 3 - Describe what you observed about the changing high-tide levels during the month and their connection to the moon phase. Reference your line graph.
   Paragraph 4 - Explain why the high-tide level changes during the month. Reference your diagram of the earth-moon-sun relationships throughout the month of April. Explain why the tide is highest under one particular phase of the moon.
3. Organization
   The report should be in the following order:
   A. Cover page with the project title, your name, and your section number filled in.
   B. Written report.
   C. Moon diary for April 2002
   D. Graph of high-tide versus time
   E. Diagram of earth-sun-moon relationships during the month.
   

Projects are evaluated as follows: accuracy of observations on moon diary (25 points) (sample attached), demonstration of accurate graphing skills (25 points) (sample attached), accuracy of explanation and sketches (25 points), neatness, spelling, grammar, etc. (15 points), due dates met (10 points). The scoring rubric follows.

Acknowledgments
The moon phase demonstration was modeled after a demonstration by Paul Rockman at the New Jersey Science Teachers' Convention. Moon phase jpg's and information from http://tycho.usno.navy.mil/vphase.html, United States Naval Observatory.