Lesson 4: Tides and Gravitational Interactions in the Sun–Earth–Moon System
Duration of Days: 5
Lesson Objective
Students will be able to analyze how gravitational interactions between the Earth, Moon, and Sun produce ocean tides
Students will use models, real-world tidal data, and Newtonian reasoning to explain and predict tidal patterns
Students will evaluate how alignment and distance affect tidal range, timing, and variation across locations
What is the primary cause of ocean tides on Earth?
How do the Moon and Sun each contribute to tidal patterns?
Why do tides occur in predictable cycles each day?
What is the difference between spring tides and neap tides in terms of alignment?
How does gravitational strength vary with distance in the Earth–Moon–Sun system?
Why do different coastal locations experience different tidal ranges and timing?
Tide
High tide
Low tide
Gravitational force
Tidal bulge
Spring tide
Neap tide
Centripetal force
Orbit
Alignment
Lunar gravity
Solar gravity
Tidal range
Differential gravity
HS-PS2-4
Use Newton’s laws of motion and universal gravitation to explain and predict the interactions between objects in the Sun–Earth–Moon system, including tidal forces and orbital motion
HS-ESS1-2
Analyze and interpret data to explain how gravitational interactions between Earth, Moon, and Sun produce observable patterns such as tides and cyclic ocean behavior
NGSS Crosscutting Concepts
Cause and Effect
Patterns
Systems and System Models
Scale, Proportion, and Quantity
Stability and Change
Interpret tidal graphs and datasets to identify repeating ocean movement patterns
Analyze gravitational diagrams to explain how the Moon and Sun influence tides
Evaluate alignment scenarios to determine spring vs. neap tides
Construct CER explanations using scientific evidence and model-based reasoning
Students will investigate how gravitational forces between Earth, the Moon, and the Sun create predictable tidal cycles. Through modeling, data analysis, and simulations, students will examine how differences in gravitational strength and orbital alignment produce variations in tidal range and timing.
Students will also analyze real tidal data from coastal regions to connect theoretical models with observable Earth system behavior.
Activities may include:
Modeling tidal bulges using Earth–Moon–Sun simulation tools or physical models
Analyzing real tidal charts from NOAA datasets
Comparing spring and neap tide alignment scenarios using diagrams
Using simulations to predict tidal behavior over multiple lunar cycles
Applying Newton’s Law of Universal Gravitation in conceptual reasoning tasks
Graphing and interpreting tidal range over time
Purpose: Strengthen students’ ability to connect gravitational force interactions to large-scale Earth system behavior and develop predictive reasoning using real-world data and scientific models.
DOK Level: 3–4 (Strategic Thinking to Extended Reasoning)
Students connect tidal behavior to coastal navigation, fishing industries, and shoreline ecosystems
Students explore how ancient and modern coastal communities use tidal knowledge for survival and trade
Students examine modern applications including tidal energy systems, harbor engineering, and coastal flood prediction
Students may think tides are caused mainly by the Sun instead of the Moon
Students may believe the Moon pulls water only on one side of Earth
Students may assume there is only one high tide and one low tide per day everywhere
Students may think winds or weather are the primary cause of tides
Students may not understand why two tidal bulges form simultaneously
Step-by-step tidal bulge modeling with visual supports
Guided interpretation of tidal graphs and datasets
Structured comparison of spring vs. neap tide conditions
Chunked instruction for gravitational force concepts
Partner analysis of real-world tidal charts
Sentence frames for cause-and-effect explanations
Visual simulations for reinforcing alignment concepts
- Formative checks during tidal modeling activities
- Vocabulary quizzes on tides and gravitational terms
- Graph analysis of real tidal data sets
- CER written explanations of tidal formation
- Diagram labeling of Earth–Moon–Sun tidal interactions
- Exit tickets predicting tidal patterns based on lunar phase and alignment
- Earth–Moon–Sun simulation tools or digital models
- NOAA tidal charts and datasets
- Interactive gravitational force simulations
- Diagrams of tidal bulges and alignment scenarios
- Tidal graphing and prediction worksheets
- Visual media on coastal tides and ocean systems