How Are Moon Phases and Tides Related?: A Graphical Model

Learning Resource Type

Lesson Plan

Subject Area

Science

Grade(s)

6

Overview

Students will complete a data table using authentic tide predictions from the National Oceanic and Atmospheric Administration. Next, students will use their data table to create a line graph that will show the relationship between the tidal range and moon phases. Lastly, students will analyze their graph to explain how the occurrence of ocean tides is related to the moon's phases. 

This lesson results from a collaboration between the Alabama State Department of Education and ASTA.

Science (2015) Grade(s): 6

SC15.6.1

Create and manipulate models (e.g., physical, graphical, conceptual) to explain the occurrences of day/night cycles, length of year, seasons, tides, eclipses, and lunar phases based on patterns of the observed motions of celestial bodies.

UP:SC15.6.1

Vocabulary

  • Model
  • Earth
  • Moon
  • Sun
  • Orbit
  • Rotation
  • Axis
  • Tilted
  • Day
  • Night
  • Hour
  • Revolution
  • Constant
  • Orbital plane
  • Orientation
  • Solar Energy
  • Equator
  • Poles
  • Northern Hemisphere
  • Southern Hemisphere
  • Winter
  • Summer
  • Tides
  • Gravitational pull
  • Low tide
  • High tide
  • Eclipse
  • Solar eclipse
  • Lunar Eclipse
  • Lunar phases (new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent)
  • Illumination

Knowledge

Students know:
  • Earth rotates on its tilted axis once in approximately 24 hours; this rotation is considered an Earth day. Due to the rotation of the Earth, the side of the Earth facing the sun experiences light (day); the side of the Earth facing away from the sun experiences dark (night).
  • The Earth-moon system revolves around the sun once in approximately 365 days; this revolution is considered an Earth year.
  • The distance between Earth and the sun stays relatively constant throughout the Earth's orbit.
  • The Earth's rotation axis is tilted with respect to its orbital plane around the sun. Earth maintains the same relative orientation in space, with its North Pole pointed toward the North Star throughout its orbit.
  • Solar energy travels in a straight line from the sun and hits different parts of the curved Earth at different angles — more directly at the equator and less directly at the poles.
  • Because the Earth's axis is tilted, the most direct and intense solar energy occurs over the summer months, and the least direct and intense solar energy occurs over the winter months.
  • The change in season at a given place on Earth is directly related to the orientation of the tilted Earth and the position of Earth in its orbit around the sun because of the change in the directness and intensity of the solar energy at that place over the course of the year.
  • Summer occurs in the Northern Hemisphere at times in the Earth's orbit when the northern axis of Earth is tilted toward the sun.
  • Summer occurs in the Southern Hemisphere at times in the Earth's orbit when the southern axis of Earth is tilted toward the sun.
  • Winter occurs in the Northern Hemisphere at times in the Earth's orbit when the northern axis of Earth is tilted away from the sun.
  • Winter occurs in the Southern Hemisphere at times in the Earth's orbit when the southern axis of Earth is tilted away from the sun.
  • A tide is the daily rise and fall of sea level.
  • Low tide is the lowest sea level at a particular time and place on Earth.
  • High tide is the highest sea level at a particular time and place on Earth.
  • Tides occur as a result of the moon's gravitational pull on the Earth.
  • Solar energy is prevented from reaching the Earth during a solar eclipse because the moon is located between the sun and Earth.
  • Solar energy is prevented from reaching the moon (and thus reflecting off of the moon to Earth) during a lunar eclipse because Earth is located between the sun and moon.
  • Because the moon's orbital plane is tilted with respect to the plane of the Earth's orbit around the sun, for a majority of time during an Earth month, the moon is not in a position to block solar energy from reaching Earth, and Earth is not in a position to block solar energy from reaching the moon.
  • A lunar eclipse can only occur during a full moon.
  • The moon rotates on its axis approximately once a month.
  • The moon orbits Earth approximately once a month.
  • The moon rotates on its axis at the same rate at which it orbits Earth so that the side of the moon that faces Earth remains the same as it orbits.
  • The moon's orbital plane is tilted with respect to the plane of the Earth's orbit around the sun.
  • Solar energy coming from the sun bounces off of the moon and is viewed on Earth as the bright part of the moon.
  • The visible proportion of the illuminated part of the moon (as viewed from Earth) changes over the course of a month as the location of the moon relative to Earth and the sun changes. This change in illumination is known as the lunar phase.
  • The moon appears to become more fully illuminated until "full" and then less fully illuminated until dark, or "new," in a pattern of change that corresponds to what proportion of the illuminated part of the moon is visible from Earth.
  • The lunar phase of the moon is a result of the relative positions of the Earth, sun, and moon.

Skills

Students are able to:
  • Develop a model of the Sun-Earth-Moon systems and identify the relevant components.
  • Describe the relationships between components of the model.
  • Use patterns observed from their model to provide causal accounts for events and make predictions for events by constructing explanations.

Understanding

Students understand that:
  • Patterns in the occurrences of day/night cycles, length of year, seasons, tides, eclipses, and lunar phases can be observed and explained using models based on observed motion of celestial bodies.

Scientific and Engineering Practices

Developing and Using Models

Crosscutting Concepts

Patterns

Primary Learning Objectives

Students will create a graphical model of the Earth's tidal pattern.

Students will analyze the graph to explain how tidal patterns and moon phases are related.

Additional Learning Objective(s)

Students will complete a data table using information from the National Oceanic and Atmospheric Administration (NOAA).

Students will use their completed data table to create a line graph showing the tidal pattern of a particular location.

Procedures/Activities

Before Strategy/Engage: 10 minutes

  1. Show students the following video clip of the tides rising and falling in the Bay of Fundy: "50 ft. tides in Burntcoat Head Park, Nova Scotia".
  2. Quick Write: After viewing this video, give students two minutes to write an answer to this question: What do you think caused the water levels to change so much in this location over one day?
  3. The teacher should ask several students to share their explanations.

During Strategy/Explore & Explain: 60 minutes

  1. Students will need the "Tidal Pattern Data Table" handout.
  2. Students will go to this website http://tidesandcurrents.noaa.gov/tide_predictions.html. Students can choose the state and specific location they would like to gather data from, or the teacher can specify a particular location. On the website, on the right side of the page, under “Published Tide Tables Formats”, students will click “Annual PDF”. Then students will scroll down to the second page of the PDF and use that information to complete their data table.
  3. Students will complete the data table as instructed on the "Tidal Pattern Data Table" handout. The teacher may model the completion of the data table for students.
  4. After completing the data table, students will analyze their data by making a line graph to represent the tidal patterns over the year. The students will need graph paper for this portion of the lesson. The students will develop a title for their graph, then label the y-axis "Tidal Range" and the x-axis "Date". Students will choose one color to plot the points of the quarter moon phases, and another color to plot the points of the new and full moon phases. Students should include a key on their graph to show what each color represents.

Note: Depending on the students' abilities and experience in creating line graphs, the teacher may want to specify the graph intervals. Alternatively, the teacher could provide a graph pre-labeled with appropriate intervals.

After Strategy/Explain & Extend: 20 minutes

  1. After completing their graph, students will answer the questions on the "Tidal Pattern Reflection Questions" handout. This handout will require students to analyze their graph and explain how the tidal patterns relate to the moon phases. 

Assessment Strategies

The teacher will informally assess students as they complete the data table and line graph to ensure students are recording and graphing information correctly.

The teacher will formally assess students during the After Strategy as students complete the "Tidal Pattern Reflection Questions" handout. The teacher can count this assessment as a course grade or use this reflection handout to facilitate a class discussion on the implications of the graph. See the answer key here.

Acceleration

Students who meet the Primary Learning Objective can use their completed "Tidal Pattern Data Table" to create a virtual graph using the following website: "Create A Graph". Students can compare their virtual graph to their paper graph by answering the following question: What are the advantages and limitations of each graphical representation? 

Intervention

Students who struggle with the graphing portion of this lesson may be partnered with a student who excels in math in order to receive support as they create the graph. The teacher should also provide support as these students work to complete the graphic portion of this lesson. The teacher could provide a completed data table for struggling students. In addition, rather than requiring the student to create the entire graph, the teacher could provide a graph with the axes and intervals already labeled. 

Total Duration

61 to 90 Minutes

Background/Preparation

The teacher and students should understand that while currents, tides, and waves are related, there are key differences between these natural oceanic occurrences. Currents are large bodies of water that move in a specific direction within the ocean. Currents are mainly caused by differences in the density of ocean water. Tides are the regular rise and fall of ocean water, caused by the effect of gravity from the sun and moon. Waves are movements of the ocean surface, usually caused by the wind. 

In addition, students should be able to recognize and identify moon phases, as well as the positions of the Earth, moon, and sun during each phase. Students should also have experience in creating a line graph based on a data table.

Materials and Resources

Calculator

Pencil

Ruler

Graph paper

Notebook paper

Colored pencils

"Tidal Pattern Data Table" handout (1 copy per student)

"Tidal Pattern Reflection Questions" handout (1 copy per student)

For the teacher: "Tidal Pattern Reflection Questions" Answer Key

Technology Resources Needed

Student digital device-laptop/tablet (if available)

Teacher computer with internet capabilities

Interactive Board or projector

"50 ft. tides in Burntcoat Head Park, Nova Scotia" Video Clip (0:47 minutes)

"NOAA Tide Predictions" website

"Create A Graph" website for extension activity

Approved Date

2016-08-22
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