# Week 2 integrated guide — Sun–Earth model and its limits

**Version:** v0.1, 29 September 2026. **Five 35-minute sessions.** Draft for educator, science, accessibility and local-syllabus review. Children use an [original two-position schematic](sun-earth-model.svg), [PNG preview](sun-earth-model.png) and [plain-text alternative](#original-plain-text-model-and-explanation-card) to connect Earth's rotation, tilted axis and revolution with day/night and **qualitative** changing day length. The diagram is **not to scale**, does not supply local sunrise times and does not model every seasonal factor. Use [English](../english/term-1/weeks-01-02/lessons.md) source language to critique it; do not double-score daily maths coordinates as astronomy.

**National links:** AC9S6U02 (movement of Earth/other planets relative to Sun; tilt, rotation, revolution and cyclic observable phenomena including variable day/night length); AC9S6I01 (reasoned questions/predictions), AC9S6I04 (use model to organise), AC9S6I05 (limits/error/questions), AC9S6I06 (communicate). Exact Year 6 content records checked against [ACARA v9 download](https://www.australiancurriculum.edu.au/downloads), retrieved 29 September 2026, pinned workbook SHA-256 `db446882d2c00cf7c085a03e250e2442fda6c44011fc114680c46c1dc7a822c3`. The pack teaches **partial** content and does not claim a full astronomy unit.

**Primary factual sources:** [NASA Earth facts](https://science.nasa.gov/earth/facts/) gives Earth's axial tilt about 23.4°, rotation about one day and one orbit about 365.25 days; its tilt explanation connects opposite hemisphere seasons. [NASA's seasons explanation](https://science.nasa.gov/helio-and-you-seasons-on-earth-mars-and-beyond/) explains the tilted axis and orbit. [NASA's day-length discussion](https://science.nasa.gov/earth/earth-observatory/an-epic-view-of-the-seasons/) explains longer days when a hemisphere tilts toward the Sun. NASA's [heliosphere learning book](https://assets.science.nasa.gov/content/dam/science/hpd/heat/heat-pdfs/2026_Journey%20Through%20the%20Heliosphere_E-Book.pdf) defines axial tilt as the angle between the spin axis and the line **perpendicular** to the orbit plane; this avoids an ambiguous phrase on the Earth facts page. The original schematic is a teaching model, not a copy of a NASA image. We use approximate `24 hours`, `365 days` and `23.4°`; do not treat them as exact clock or orbital measurements made by children.

**Safety/access:** Do **not** view the Sun directly or through lenses, make pupils stare at bright lamps, use hot bulbs, darken exits or handle mains electrical apparatus. The paper diagram suffices. Optional teacher-controlled cool light/globe follows school science rules; no child has to stand or manipulate a globe. Provide tactile circles/axis line, large print, text route, screen reader, sign/AAC or adult-directed movement. A child can challenge a model's limit without drawing it neatly. Do not infer a pupil's location, cultural calendar or seasonal experience from an assumed country.

## Day 1 — Rotation and the day/night boundary

**Question:** What does Earth's spin help explain? **35 = 5 retrieve + 7 model + 12 trace + 8 discuss + 3 check.**

1. **Retrieve 5:** Ask what is moving in a day/night explanation. Record ideas; distinguish the Sun's apparent movement from Earth's rotation.
2. **Model 7:** Teacher points to a paper Earth circle with half facing a drawn Sun. “Earth rotates on its axis. A place turns into and out of sunlight over roughly 24 hours, giving day and night.” Avoid claiming the side in shade stays dark all season.
3. **Trace 12:** Learners move one marked place around a paper Earth circle once, saying/indicating light → dark → light. Use child-directed adult rotation/tactile marker. Label this **rotation**, not revolution.
4. **Discuss 8:** Ask whether a paper circle proves exact sunrise time. **Key:** no; it omits location/date and is not a measurement. Show how an observer may describe a changing day/night pattern from model only.
5. **Check 3:** “Which motion gives a day/night cycle in this model?” **Key:** Earth rotating on its axis. **Next:** if learner says orbit alone, compare spin in place with movement around Sun.

## Day 2 — Revolution and an axis that stays tilted

**Question:** How are spin and orbit different? **35 = 5 compare + 7 model + 12 build + 8 explain + 3 check.**

1. **Compare 5:** Put `rotation ≈ one day` and `revolution ≈ one year` cards. Ask learners to match motions.
2. **Model 7:** Teacher traces Earth around a fixed Sun on diagram while drawing axis leaning the **same direction in space** at two orbit positions. “One orbit is about 365 days; the axis is tilted about 23.4° relative to a line perpendicular to the orbit plane.” Scale and duration are schematic.
3. **Build 12:** Learners use two paper Earth circles or tactile models left/right of Sun, aligning both axis arrows parallel. Rotate a small place marker on each; orbit and spin can occur together.
4. **Explain 8:** Children name one feature the model shows (parallel tilt arrows) and one it omits (actual distances, orbital shape/time at each point, exact day length).
5. **Check 3:** “At the opposite position, do we reverse the direction the north end of the axis points in space?” **Key:** no, keep approximately parallel in this model. **Next:** align two printed axis arrows before discussing seasons.

## Day 3 — Two hemisphere positions, opposite seasonal tendency

**Question:** What changes when each hemisphere tilts toward/away from Sun? **35 = 5 predict + 7 model + 12 compare + 8 critique + 3 check.**

1. **Predict 5:** In left model position, north end tilts toward drawn Sun; ask which hemisphere gets more direct sunlight and longer daylight in this simplified solstice-like comparison. **Key:** Northern Hemisphere.
2. **Model 7:** Point to right position six months around orbit: axis still points same way in space, so south end now tilts toward Sun. “Southern Hemisphere has more direct sunlight and longer daylight in this comparison.” This is a seasonal tendency, not a local weather forecast.
3. **Compare 12:** Learners place `longer daylight in north`/`longer daylight in south` cards on positions; explain with tilt line and Sun direction. Use tactile arrow or read text alternative.
4. **Critique 8:** Teacher proposes “Summer happens because Earth is much closer to the Sun in December.” Learners reject distance as primary explanation for opposite hemisphere seasons in this model, citing tilt and orientation. Do not suggest Earth's orbit is perfectly circular.
5. **Check 3:** “When the Northern Hemisphere tilts toward Sun in our left position, which hemisphere has longer days?” **Key:** north. **Next:** physically place north arrow toward Sun and trace longer daylight side.

## Day 4 — A model can predict a pattern, not a clock time

**Question:** How can day length differ across the year? **35 = 5 recall + 7 model + 12 sequence + 8 limits + 3 check.**

1. **Recall 5:** Retrieve rotation for day/night and tilt+orbit for seasonal variation. Require both mechanisms to be named, not a memorised diagram caption.
2. **Model 7:** Teacher places a middle-position card: hemispheres are more evenly lit near an equinox-like arrangement; avoid claiming exactly 12 hours everywhere on a named date. “Our two-position drawing does not locate this exactly.”
3. **Sequence 12:** Learners arrange north-toward, intermediate, south-toward, intermediate cards for an annual cycle, then state qualitative day length in the Southern Hemisphere: longer toward-sun phase, shorter away phase. Do not use “hotter” as the day-length measure.
4. **Limits 8:** Ask for data needed to determine an actual sunrise time: place/date and an authoritative astronomical or meteorological source. The paper model has none. Do not record made-up sunrise values for any location.
5. **Check 3:** “What changes day length over the year: the daily spin alone, or tilt plus revolution?” **Key:** tilt plus revolution changes the pattern, while rotation produces each day/night cycle. **Next:** trace one spin at two orbital positions.

## Day 5 — Explain and revise a scientific model

**Question:** Can a peer follow an accurate explanation and see its limits? **35 = 5 plan + 7 model + 12 create + 8 peer check + 3 exit.**

1. **Plan 5:** Learners choose text, tactile diagram, signed/AAC presentation, labelled drawing or child-directed adult model. Give success criteria: rotation/day-night, tilted-axis+revolution/day-length, hemispheres and one model limit.
2. **Model 7:** Teacher offers three sentences with source: “Earth rotates, so a place passes into and out of sunlight. As tilted Earth revolves around Sun, which hemisphere leans toward Sun changes over the year. This paper diagram cannot give the exact sunrise time.” Keep `about` for numerical facts.
3. **Create 12:** Each learner makes their explanation with arrows/labels/words and cites NASA/ACARA source line as teacher-provided science reference. No copied external diagram.
4. **Peer check 8:** Partner tests a common wrong claim (“seasons caused mainly by distance”; “axis flips between positions”) against model and source. Revise one line. Avoid mocking an initial misconception.
5. **Exit 3:** “Name one thing this model can explain and one it cannot.” **Key:** day/night/qualitative day length; cannot give exact local times or scale. **Next:** revisit the missing mechanism and recheck with a fresh position card.

## Original plain-text model and explanation card

```text
SUN (not to scale)
LEFT ORBIT POSITION:  Earth at left of Sun; north end of tilted axis
                      leans RIGHT, toward Sun → Northern Hemisphere
                      has longer daylight in this comparison.
RIGHT ORBIT POSITION: Earth at right of Sun; north end of axis still
                      leans RIGHT, away from Sun → Southern Hemisphere
                      has longer daylight in this comparison.
EARTH ROTATES on its own axis ≈ 24-hour day/night cycle.
EARTH REVOLVES around Sun ≈ 365-day year; tilt ≈ 23.4°.
AXIS arrows stay roughly parallel in space in the two positions.
This is a simplified two-position model, not actual local time data.

MY CLAIM: ______________________________________________
SOURCE/DIAGRAM DETAIL: __________________________________
MECHANISM: rotation / tilt / revolution (explain) ______
ONE MODEL LIMIT: ________________________________________
RESPONSE MODE / SUPPORT: ________________________________
```

**Evidence boundary:** The teacher checks mechanism and model critique, not a pupil's art or fluency. No exact seasonal daylight number, astronomy photograph or real Sun observation is fabricated. Use school-adopted scientific conventions if supplementing the model.

**Rights:** Original guide/card/diagram © NeuroForgeIO Pty Ltd 2026, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). Credit *SubjectNest Year 6 Australian-first opening pack*, v0.1, [source](https://github.com/neuroforge-io/neuroforge_business/tree/main/products/curriculum-studio/content/year-6/term-1), licence and changes. ACARA and linked NASA material retain separate rights; no third-party image is reproduced. [Integrated-file hashes](manifest.sha256). Educator/science/access review pending.