Lab 08b: sky: polynesian navigation

🌊✨ Ocean Navigation by the Stars — Using Star Walk

🧭 Lesson 1 — Finding Direction with the Sky

Objective: Understand how stars move across the sky and how their patterns indicate direction.

Key Concepts:

• Apparent motion of stars due to Earth’s rotation

• Polaris (North Star) as a fixed directional marker

• Southern Cross as a southern hemisphere guide

Activity:

1. Open Star Walk and set location to your local coordinates.

2. Observe the sky through the app at sunset and identify Polaris (Northern Hemisphere) or Crux (Southern Hemisphere).

3. Note how the stars rotate around these points using the app’s time-lapse function.

4. Discuss:

Extension:

Draw your horizon and label east, west, and Polaris’ position relative to your latitude.

🌍 Lesson 2 — Latitude from the Stars

Objective: Measure and interpret star altitude to estimate latitude.

Key Concepts:

• Altitude = angle above horizon

• Polaris’ altitude ≈ observer’s latitude

• Relationship between horizon, zenith, and celestial sphere

Activity:

1. Use Star Walk to locate Polaris and note its altitude on-screen.

2. Compare to your known latitude (Star Walk provides this).

3. Repeat at different simulated locations (change city in app).

4. Record:

5. Discuss why southern hemisphere navigators use other stars instead.

Extension:

Students create a mini “sextant” using a straw, protractor, and string to measure altitude of Polaris outside.

🌊 Lesson 3 — Wayfinding Like the Polynesians

Objective: Explore how Pacific navigators used star lines and ocean cues.

Key Concepts:

• Polynesian star compass

• Star rising and setting points

• Integration of ocean swells, wind, and birds in navigation

Activity:

1. Use Star Walk to locate Orion, Sirius, and Pleiades.

2. Note the compass direction where each rises and sets.

3. On a circular “star compass” diagram, label these as navigation points.

4. Discuss:

Extension:

Watch short video or diagram of the Polynesian star compass (Te Lapa) and compare to your own diagram.

🌅 Lesson 4 — Seasonal Shifts and Ocean Routes

Objective: Understand how seasonal constellations guided long voyages.

Key Concepts:

• Earth’s orbit and seasonal visibility of constellations

• Relationship between star visibility and hemisphere position

• Using changing skies to track time and season

Activity:

1. In Star Walk, advance the date month by month.

2. Watch how constellations rise earlier or disappear.

3. Identify which stars were visible during traditional Pacific voyages.

4. Discuss how ancient navigators planned routes according to seasonal star maps and trade winds.

Extension:

Students write a short reflection:

“If I were sailing from Hawaiʻi to Tahiti, what star paths would I follow, and how would I know when to turn?”

🌌 Lesson 5 — Modern and Ancient Navigation

Objective: Compare celestial navigation to GPS and modern instruments.

Key Concepts:

• Transition from celestial navigation → radio → satellite

• How both rely on precise timing and position

• Cultural importance of preserving wayfinding knowledge

Activity:

1. Use Star Walk to simulate positions of key stars during an ocean crossing.

2. Compare how ancient navigators used angular measurements vs. how GPS triangulates satellite signals.

3. Discussion prompts:

• What knowledge is lost if we stop looking at the sky?

• How could modern tools and ancient techniques complement each other?

Extension:

Have students design a hybrid “digital star compass” — combining AR sky data and real compass direction — and describe how it could help sailors or hikers offline.

🧩 Assessments possible:

• Creative Project: Students create a star navigation logbook tracing a fictional voyage using Star Walk screenshots and reflections.

• Performance Task: In pairs, students “sail” across the virtual Pacific, using only star rise/set directions in the app to explain their route.

• Reflection Essay:

“What can celestial navigation teach us about observation, patience, and interconnectedness between Earth and sky?”

1. Storytelling 

• Begin with a short story of a Polynesian voyage (e.g., the Hōkūleʻa canoe’s modern voyages or ancient wayfinders sailing thousands of miles without instruments). See videos above

• Look up pictures of Polynesian double-hulled canoes.

• Ask: “How could they cross the ocean without GPS, compasses, or maps?”

2. Concepts of Polynesian Navigation

• Stars as compass points: Rising and setting stars mark east and west.

• Star lines: Navigators memorized ~200 stars and their rising/setting positions.

• Dead reckoning: Estimating speed/direction over time.

• Environmental cues: Ocean swells, clouds, bird flight patterns.

• Use a globe or map to show how far voyages reached (Hawai‘i, Tahiti, Aotearoa).

3. Star Simulator Exploration 

• Open the iPad star simulator (e.g., SkySafari, Star Walk, or Stellarium).

• Find Polaris vs. Southern Cross: Compare northern vs. southern navigation.

• Identify a star line: Pick a canoe course (say east) and have students mark which stars rise/set at that bearing.

• Simulate voyaging at sea: Dim lights, have students “steer” by keeping their iPad pointed at a chosen guiding star.

• Star compass activity: Assign groups a quadrant (north, east, south, west). Each group records which stars rise/set in their direction and shares back to create a full class “star compass.”

4. Hands-On Simulation (Optional Extension, 15 min)

• In pairs, one student is the “navigator” holding the iPad, the other is the “crew.”

• The navigator gives directions based on a guiding star (“Keep the canoe under Orion’s belt, rising in the east”).

• Rotate roles.

5. Wrap-Up & Reflection (10 min)

• Discuss: “What would be hardest about navigating this way?”

• Connect to science: role of Earth’s rotation, star paths, and latitude in navigation.

• Reflection prompt: “If GPS stopped working tomorrow, what knowledge from Polynesian navigation would still help us?”