Earth, Sun and Moon: a full term of science

Ten ready-to-teach lessons for Year 7 Earth and space sciences. Print this pack and the term is prepared: every lesson comes with a step-by-step plan, the questions to ask, a student worksheet, cut-out cards, a practical sheet or exit tickets, an assessment kit and worked answers.

Start here: five minutes to Monday

1. Skim the term at a glance on the next page.
2. Print the lesson you need. Each lesson is three A4 sheets: plan, worksheet, and cards, a practical sheet or tickets.
3. Gather the few items under “You need” on the plan. Most come from the classroom or the sports shed.
4. Open the free interactive unit on your board or projector. Every plan tells you which picture to show and when.
5. Teach straight from the plan. Timings, talk prompts, misconceptions and worked answers are all on the one page.

For any Year 7 science teacher

The pack suits a science specialist and a teacher working outside their own subject alike: each plan explains the idea in plain words, lists the misconceptions students bring, and gives worked answers. The big idea of the term: the Earth spins once a day and orbits the Sun once a year with its axis tilted, and the Moon orbits the Earth about once every 29.5 days. These steady cycles give us day and night, the Moon’s phases, eclipses when the three bodies line up, the seasons and the tides, and because the cycles are steady, all of them can be predicted.

Two ways to run each lesson

Every lesson works as one 60-minute block, or as two 30-minute sessions; the split point is marked in every plan. Look ahead: Lessons 2 and 4 need a room you can darken, Lesson 3 hands out a Moon diary for the next two weeks, and Lesson 5 needs sunshine (Lesson 7’s shadow task works best near noon on a sunny day).

Safety and care in one look

No one ever looks at the Sun, with bare eyes or through a lens, a pinhole or sunglasses; the pinhole viewer is used with your back to the Sun. Lamps get hot, and cords trip people in a darkened room. Outdoors, students wear hats and sunscreen.

The term at a glance

One lesson a week for a term. Each lesson stands on the ones before it, so run them in order where you can.

How the sequence builds

Lessons 1 to 3 build the cycles: the day, then the Moon’s phases and its month. Lessons 4 and 5 line the bodies up: eclipses, and a pinhole measurement of the Sun that is also the safe way to watch one. Lessons 6 and 7 explain the seasons, first with a model and then with data from four cities. Lesson 8 adds the tides, Lesson 9 the Moon’s one face and the true scale of the system, and Lesson 10 turns it all into predictions.

Curriculum links (Australian Curriculum V9)

The whole term teaches the Science Understanding descriptor AC9S7U03 quoted on the cover. The lessons also work these Science Inquiry and Human Endeavour descriptors:

Assessment in this pack

• Every plan ends with “Answers and look-fors”: what meeting the idea sounds like in a Year 7 voice, with working.
• The assessment sheet near the front has a class observation checklist and a three-level rubric.
• Lesson 10 is the summative pair: predictions for the coming weeks, plus the “Show what we know” check.

Materials for the whole term

One gathering session covers all ten lessons. Most of the kit is a lamp, some balls and the cards in this pack; Lesson 5 needs long boxes or tubes, which are worth collecting a few weeks ahead. Plan the weather too: Lesson 5 needs sunshine, and Lesson 7’s shadow task works best near noon on a sunny day.

The one-trip list

• From the classroom: calculators, rulers, protractors, scissors, tape, white paper, 1 cm grid paper, torches and a globe.
• From the craft shop or supermarket: polystyrene balls about 6 cm across (one per student), aluminium foil and pins.
• From the sports shed: a basketball, a tennis ball, a hula hoop, a metre ruler and a long tape measure or trundle wheel.
• To collect: long boxes or cardboard tubes about 1 m long (poster tubes or wrapping-paper tubes), one per group.

Safety and care in one look

• No one ever looks at the Sun: not with bare eyes, sunglasses, a lens or through the pinhole. The pinhole viewer is used with your back to the Sun.
• Lamps get hot; keep paper clear of the bulb, and tape cords down before the room is darkened.
• Pins and scissors are handled by the person using them, and the pin goes back in its box.
• Outdoors: hats and sunscreen, and short spells in the sun.

Assessment without extra work

The term assesses itself. Every lesson plan ends with worked answers and look-fors, and Lesson 10 is the summative pair: the prediction task, in which students use the cycles to forecast the coming weeks, and the final check. This sheet is the place to note what you see along the way.

The three levels

Class observation checklist

A tick a lesson is plenty; the Lesson 10 task and check fill the gaps.

Word wall cards

Cut out the cards and build the wall as the words arrive: rotation, axis and orbit in Lesson 1; phase, waxing and waning in Lesson 2; lunar month in Lesson 3; solar eclipse and lunar eclipse in Lesson 4; solstice and equinox in Lesson 6; latitude in Lesson 7; tide and spring tide in Lesson 8; scale model in Lesson 9.

Dear families

This term in science, Year 7 studies the Earth, the Sun and the Moon: how the Earth’s spin gives us day and night, why the Moon changes shape through the month, what lines up during an eclipse, why we have seasons, and why the sea rises and falls twice a day. The big idea is that these are all cycles, and cycles can be predicted.

Along the way your student will model the Moon’s phases with a lamp and a ball, keep a Moon diary for two weeks, build a pinhole viewer and use it to work out how big the Sun is, test why low winter sunlight is weaker, read a tide table, and build the Earth, the Moon and the Sun to scale (the Sun ends up nearly three kilometres away).

Try this at home

• Help with the Moon diary: on clear nights, look for the Moon together and sketch its shape and where it is in the sky.
• Notice where the Sun sets from your street, and check again in a month. Has the spot moved?
• Look up the tide times for the nearest coast. How much later is high tide each day?
• Find out when the next eclipse can be seen from Australia. On 22 July 2028 a total solar eclipse crosses the country.

What to ask your scientist

• Why does the Moon change shape?
• Why is it summer here when it is winter in Japan?
• Why are there two high tides a day, and not one?
• How did your class measure the Sun without looking at it?

A small note on safety: no one should ever look at the Sun, even during an eclipse, without proper eclipse glasses; the pinhole viewer your student builds is a safe way to watch.

Warm regards,

The Year 7 science team

Printed from the free seegongsik Earth, Sun and Moon teaching pack · seegongsik.com/au/y7/earth-and-space/AC9S7U03/pack

Day and night

The Sun does not travel round the Earth: the Earth spins on its axis once a day, from west to east, so the Sun appears to rise in the east and set in the west. Half the Earth is always in sunlight. Because the Earth turns 360° in 24 hours, solar noon, the moment the Sun is highest in a place’s sky, sweeps across Australia from east to west at 15° of longitude an hour, or 1° every 4 minutes. Students model day and night with a lamp and a globe, then use the longitudes of eight cities to work out when solar noon reaches each.

We are learning to

• explain day and night with a model of the spinning Earth,
• explain why the Sun rises in the east and sets in the west,
• calculate a difference in solar time from a difference in longitude.

Success criteria

• I can use the lamp-and-globe model to show sunrise, noon, sunset and midnight for one city.
• I can work out how much earlier solar noon comes in one city than in another.

You need

• a lamp with a bare bulb, or a bright torch on a stack of books, and a globe or a large ball with Australia marked on it,
• the worksheet (next sheet), one per student, and the exit tickets (third sheet), cut into four.

Safety: the bulb gets hot; tape the cord down before the room is darkened.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Do the model and the board in Session A, and solar noon and the ticket in Session B.

Watch for these ideas

• “The Sun goes round the Earth.” It looks that way from the ground; the spinning Earth explains the same sunrise and sunset, and the model shows it.
• “The Earth going round the Sun makes day and night.” The spin makes the day; the trip round the Sun makes the year.
• Turning the globe the wrong way. The Earth spins west to east, so the eastern cities reach the light first.

Make it easier, make it bigger

• Easier: fill the table for Darwin, Adelaide and Sydney only.
• Bigger: outside daylight saving, Adelaide’s clocks run 30 minutes behind Sydney’s, but by the Sun the gap is 50 minutes. Why don’t time zones follow the Sun exactly?

Answers and look-fors

• Part A: A sunset, B noon, C sunrise, D midnight. It is day on the half facing the lamp and night on the other half.
• Part B: Darwin 14.9°, 60 minutes (1 h); Alice Springs 18°, 72 minutes (1 h 12 min); Adelaide 22.7°, 91 minutes (1 h 31 min); Melbourne 29.1°, 116 minutes (1 h 56 min); Hobart 31.4°, 126 minutes (2 h 6 min); Sydney 35.3°, 141 minutes (2 h 21 min); Brisbane 37.1°, 148 minutes (2 h 28 min).
• Part C: 1. Brisbane: it is furthest east, so the turning Earth carries it into the Sun’s light first. 2. 50 minutes (12.6 × 4). 3. A place would have about half a year of daylight and half a year of night, as only the trip round the Sun would bring it into and out of the light.
• Bigger: a time zone covers a wide strip, so its clocks match the Sun only along one line of longitude; states also choose zones that keep their own towns together.
• Exit ticket: 1. The Earth spinning on its axis. 2. In the east, because the Earth turns from west to east. 3. 120 minutes, or 2 hours (30 × 4).

Day and night

A. The lamp-and-globe model

Write sunrise, noon, sunset or midnight for each place.

B. Solar noon across Australia

The Earth turns 15° an hour, so 1° of longitude takes 4 minutes.

C. Questions

Exit tickets

Cut into four. Students answer on their own.

Teacher note: the answers are on this lesson’s plan.

Phases of the Moon

The Moon makes no light of its own: the Sun always lights the half of the Moon that faces it. As the Moon orbits the Earth, once every 29.5 days or so, we see different amounts of that lit half, from none at new moon to all of it at full moon. Students model the phases with a lamp and a ball, then order eight phase cards drawn as the Moon looks from Australia, where the growing (waxing) Moon is lit on the left: we see the Moon the other way up from someone in Europe.

We are learning to

• explain why the Moon shows phases, using a model,
• name the eight phases in order,
• describe how the phases look from Australia.

Success criteria

• I can use the lamp-and-ball model to show and explain new moon, first quarter and full moon.
• I can put the eight phase cards in order, as seen from Australia, and explain why the lit side looks swapped.

You need

• the lamp with a bare bulb at head height at one end of a room you can darken, and for each student a polystyrene ball about 6 cm across pushed onto a pencil,
• the worksheet (next sheet), one per student, and the phase cards (third sheet), cut out, one set per pair.

Safety: clear the floor and tape the lamp cord down before the room is darkened; the bulb gets hot.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Do the model and Part A in Session A, and the board, the cards and Part C in Session B.

Watch for these ideas

• “The Earth’s shadow makes the phases.” The Earth’s shadow falls on the Moon only in a lunar eclipse; phases come from how much of the lit half faces us.
• “The Moon only comes out at night.” The Moon is often up in daylight; near first quarter it rises around midday.
• “The Moon looks the same from everywhere.” From Australia it looks the other way up from Europe, so the lit side is swapped.

Make it easier, make it bigger

• Easier: model and order only four phases first: new moon, first quarter, full moon and last quarter.
• Bigger: a full moon rises at about sunset. Use the model to work out when a first-quarter Moon rises and sets.

Answers and look-fors

• Part A: stop 1 dark; then a lit sliver on the ball’s right that grows to half at stop 3 and to fully lit at stop 5, with the lamp behind; then shrinking, lit on the left, to a sliver at stop 8. The room shows the view from the north.
• Part B: D, G, B, E, H, A, F, C; that is new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, waning crescent.
• Part C: 1. The Sun lights half the Moon; as the Moon orbits, we see more or less of that lit half. 2. We stand the other way up from someone in Europe, so we see the Moon upside down and the lit side swapped. 3. A full moon is on the opposite side of the Earth from the Sun, so it rises in the east as the Sun sets in the west.
• Bigger: about midday, setting about midnight: at first quarter the Moon is a quarter of a turn behind the Sun.

Phases of the Moon

A. Moon on a stick

Face the lamp with the ball held up in front of you (stop 1), then turn slowly to your left. Shade the dark part of the ball at each stop.

B. The phase cards

Put the cards in order as the Moon looks from Australia, starting with the new moon. Write each letter, then the name of its phase. Word bank: first quarter, full moon, last quarter, new moon, waning crescent, waning gibbous, waxing crescent, waxing gibbous.

C. Questions

Phase cards: the Moon from Australia

Cut out the eight cards. Each shows the Moon as it looks from Australia, with its lit part in gold.

Teacher note: the order is on this lesson’s plan. Keep the cards for Lessons 3 and 10.

A year of full moons

The Moon’s cycle can be measured from real dates. Students find the gaps between the twelve full moons of 2025, work out that the cycle is about 29.5 days long, and use that number to explain why the Moon rises about 50 minutes later each night and why some years have thirteen full moons. They start a two-week Moon diary to test the model against the real sky.

We are learning to

• find a pattern in real astronomical data,
• calculate an average from a set of measurements,
• use a cycle to make a prediction.

Success criteria

• I can find the gaps between full moons and the average length of the cycle.
• I can explain, with a calculation, why the Moon rises later each night.

You need

• calculators and the worksheet (next sheet), one per student,
• the Moon diary (third sheet), one per student, to keep for two weeks.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Do the full moons and the board in Session A, and Parts B and C and the diary in Session B.

Watch for these ideas

• “A month and the Moon’s cycle are the same.” Calendar months run 28 to 31 days, so the full moon drifts to a different date each month.
• Dividing by 12, the number of full moons, instead of 11, the number of gaps between them.
• “The Moon rises at the same time every night.” It rises about 50 minutes later each night; the diary will show it.

Make it easier, make it bigger

• Easier: find the gaps for the first six full moons only, and their average.
• Bigger: the Moon takes only about 27.3 days to go once round the Earth, measured against the stars, yet the phases take 29.5 days. Why the difference?

Answers and look-fors

• Part A: gaps of 29, 30, 30, 30, 29, 30, 29, 30, 29, 29, 30 days. 1. Shortest 29 days, longest 30 days. 2. (339 − 14) ÷ 11 = 325 ÷ 11 = 29.5 days.
• Part B: 1. 360 ÷ 29.5 = 12.2° a day. 2. 12.2 × 4 = about 49 minutes, so the Moon rises about 50 minutes later each day.
• Part C: twelve gaps take 12 × 29.5 = 354 days, so a thirteenth full moon fits only if the first falls in about the first ten days of January. In 2025 the first was on day 14, so there were twelve.
• Bigger: in those 27.3 days the Earth also moves about 27° further round the Sun, so the Moon must travel a little further to line up with the Sun again.
• Diary look-fors: an entry most nights, a shape that grows or shrinks steadily, and the Moon in a different place at the same time each night.

A year of full moons

A. The full moons of 2025

Dates in eastern Australian standard time.

B. Later every night

In one cycle the Moon goes 360° round its orbit, moving east. Each day the Earth must turn that much further before the Moon rises again.

C. Thirteen full moons?

My Moon diary

Look for the Moon at about the same time each night for two weeks. Draw its shape, and note the direction you face and its height: a fist held at arm’s length covers about 10° of sky. If you cannot see it in the evening, try before school the next morning, or write “not seen”. Never look at the Sun.

Bring the diary back in Lesson 5.

Eclipses

An eclipse happens when the Sun, the Earth and the Moon line up and one body’s shadow falls on another. In a solar eclipse the Moon passes between the Sun and the Earth, which can happen only at new moon; in a lunar eclipse the Earth is between the Sun and the Moon, which can happen only at full moon. Most months there is no eclipse, because the Moon’s orbit is tilted about 5° to the Earth’s, so the Moon usually passes just above or below the line. Students model both eclipses, find the pattern in the eight eclipses of 2025 and 2026, and sort twelve statements.

We are learning to

• model solar and lunar eclipses and say which body is in the middle,
• explain why eclipses happen only at new or full moon, and not every month,
• find a pattern in real eclipse dates.

Success criteria

• I can show a solar and a lunar eclipse with the lamp and two balls, and name the Moon’s phase for each.
• I can use the tilted orbit to explain why there is not an eclipse every month.

You need

• the lamp, a large ball for the Earth, a small ball on a pencil for the Moon and a hula hoop; calculators,
• the worksheet (next sheet), one per student, and the statement cards (third sheet), one set per pair.

Safety: no one looks at the Sun, even when it is partly covered; only certified eclipse glasses or a pinhole viewer are safe. The bulb gets hot.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Do the diary check, the model and the board in Session A, and the real eclipses and the sort in Session B.

Watch for these ideas

• “A lunar eclipse is just a phase.” Phases come from the angle we see the lit half from; an eclipse is a shadow.
• “Every new moon makes a solar eclipse.” The tilted orbit usually carries the Moon just above or below the line.
• “Everyone sees a total solar eclipse.” The Moon’s shadow is small, so totality is seen only along a narrow path; a lunar eclipse can be seen from the whole night side.

Make it easier, make it bigger

• Easier: model the solar eclipse first and fill its half of Part A, then the lunar eclipse.
• Bigger: on 22 July 2028 a total solar eclipse will cross Australia from the Kimberley to Sydney. What phase is the Moon that day, and when would you look for a lunar eclipse?

Answers and look-fors

• Part A: solar, the Moon in the middle, at new moon; lunar, the Earth in the middle, at full moon. The tilted orbit means the Moon usually passes above or below the line at new and full moon.
• Part B, days since the eclipse before: 15, 162, 14, 149, 14, 162, 16. Every solar eclipse is at new moon and every lunar eclipse at full moon. 1. The pairs are 15, 14, 14, 16 days apart: half the Moon’s cycle, from full moon to new moon or back. 2. Each pair starts about six months after the one before (177, 163, 176 days), a little earlier in the year each time. 3. The lunar eclipses of 14 March and 7 September 2025 match the Lesson 3 full moons of 14 March and 8 September: in eastern Australia the September eclipse fell in the early hours of 8 September.
• Part C: solar C, E, H, K; lunar A, D, G, I, L; both B, F, J.
• Bigger: new moon. Eclipses come in pairs about two weeks apart, so look at the full moons two weeks either side: a partial lunar eclipse falls on 6 July 2028.

Eclipses

A. Line them up

Draw the Sun, the Earth and the Moon in a line for each eclipse, and shade the shadow. Label the Moon’s phase.

B. Eight real eclipses

Dates in universal time, as eclipse lists give them.

C. Solar, lunar or both?

Solar, lunar or both?

Cut out the cards. Lay down the three grey heading cards and sort each statement.

Teacher note: 4 cards go under solar, 5 under lunar and 3 under both.

Measuring the Sun

A pinhole makes an upside-down image of the Sun on a screen, and it is a safe way to watch an eclipse. Light from the top and bottom of the Sun crosses at the pinhole, so the Sun and its image form two triangles of the same shape: the Sun’s diameter is to its distance as the image is to the pinhole-to-screen distance. With a 1 m viewer the image is only about 9.3 mm across, but measured with care it shows that the Sun is about 1.4 million kilometres wide.

We are learning to

• build a pinhole viewer and use it safely,
• measure a small length with care, repeat it and average,
• use a ratio to calculate a size we cannot measure directly.

Success criteria

• I can measure the Sun’s image to the nearest half millimetre, three times, and average the results.
• I can calculate the Sun’s diameter from my measurements and compare it with the accepted value.

You need

• for each group: a long box or cardboard tube about 1 m long, aluminium foil, a pin, tape, white paper, scissors and a ruler; a sunny day,
• the worksheet (next sheet), one per student, and the build sheet (third sheet), one per group.

Safety: no one looks at the Sun, with bare eyes, sunglasses or through the pinhole. Stand with your back to the Sun and look only at the image inside the box. Pins are handled by the person using them. Hats and sunscreen outside.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Build and measure in Session A on a sunny day; calculate and discuss in Session B.

Watch for these ideas

• “Sunglasses make it safe to look at the Sun.” They do not; only certified eclipse glasses or a projected image are safe.
• “A bigger pinhole gives a bigger image.” It gives a brighter, blurrier image of the same size; the size depends on L.
• Mixing units: keep d and L both in millimetres, so their ratio has no units.

Make it easier, make it bigger

• Easier: use the example class results, and give the formula D = d ÷ L × 150 000 000 km.
• Bigger: the Moon is about 384 400 km away and looks the same size as the Sun. Use the same ratio to estimate its diameter.

Answers and look-fors

• Part A: images of about 9.3 mm on a 1000 mm viewer; three readings within about 1 mm of each other.
• Part B, example class: (9 + 10 + 9 + 9.5 + 8.5 + 9) ÷ 6 = 9.2 mm; 9.2 ÷ 1000 × 150 000 000 = about 1 380 000 km (1 375 000 km with the unrounded mean). The accepted value is about 1 392 000 km, so the example class was within about 2%.
• Part C: 1. Any two: the image edge is fuzzy; the pinhole is not a perfect point; the box bends, so L changes; a half-millimetre reading is a big fraction of a 9 mm image. 2. A 2 m viewer makes the image twice as big, so the same reading error is half as big a fraction. 3. You look at the image on the screen, with your back to the Sun, never at the Sun itself.
• Bigger: the Moon’s diameter is to 384 400 km as 9.3 is to 1000, which gives about 3600 km (the accepted value is 3474 km).

Measuring the Sun

A. Our measurements

Clouds? Use the example class: L = 1000 mm, and six readings of d: 9, 10, 9, 9.5, 8.5, 9 mm.

B. How wide is the Sun?

C. Errors and eclipses

Build a pinhole viewer

Steps

1. Cut a hole about 2 cm across in the centre of one end of the box or tube.
2. Tape a square of foil over the hole, smooth and tight, and push the pin through its centre once to make one clean, round pinhole.
3. Tape white paper flat across the inside of the other end: this is the screen.
4. Cut a viewing window in the side, near the screen end, big enough to see the screen.
5. Outside, stand with your back to the Sun and hold the pinhole end up over your shoulder. Move the box until its shadow is smallest: the bright round image will appear on the screen.
6. Mark the two edges of the image with pencil dots across its widest part, then measure between the dots. Measure L, from the foil to the screen.

What is happening

The same viewer will show a partial solar eclipse safely: the round image of the Sun becomes a crescent as the Moon moves across it. On 22 July 2028 a total solar eclipse crosses Australia from the Kimberley to Sydney, and the whole country will see at least a partial eclipse.

Why we have seasons

The Earth’s axis is tilted about 23.4° and keeps pointing the same way in space as the Earth orbits the Sun. For half the year the Southern Hemisphere leans towards the Sun: the noon Sun climbs higher, its light falls more directly and is more concentrated, and the days are longer, so it is summer. Half a year later the south leans away and it is winter. Distance is not the cause: the Earth is closest to the Sun in early January, during our summer but during the northern winter. Groups test how the angle of a torch beam changes how concentrated the light is, then weigh the distance idea against data.

We are learning to

• explain how the angle of sunlight changes the energy each square metre receives,
• explain the seasons with the tilted axis,
• use evidence to reject an explanation that does not fit.

Success criteria

• I can use the torch results to explain why low sunlight is weaker.
• I can explain why Australia has summer in December, and give evidence against the distance idea.

You need

• for each group: a torch, 1 cm grid paper, a protractor and a ruler; the lamp and the globe,
• the worksheet (next sheet), one per student, and the exit tickets (third sheet), cut into four.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Do the torch test in Session A, and the globe, the board, Parts B and C and the ticket in Session B.

Watch for these ideas

• “Summer is when the Earth is closest to the Sun.” The Earth is closest in early January, which is winter in the north.
• “Leaning towards the Sun puts us closer to it.” The lean moves Australia a few thousand kilometres at most, out of 150 million; it is the angle of the light that matters.
• “The axis flips over during the year.” It points the same way in space all year; the Earth moves to the other side of the Sun.

Make it easier, make it bigger

• Easier: test only 90° and 30°, and compare the two patches.
• Bigger: in Darwin, the seasons are wet and dry rather than hot and cold. Use the torch results to explain why Darwin is warm all year: even in June its noon Sun is 54.1° high.

Answers and look-fors

• Part A, example class: 90° 20 squares, 5 each; 60° 23 squares, 4.3 each; 45° 28 squares, 3.6 each; 30° 40 squares, 2.5 each. The lower the beam, the bigger the patch and the less light each square receives: at 30° each square gets about half as much as at 90°.
• Part B: 1. Summer. 2. Winter: the Northern Hemisphere has winter in January, so if distance caused the seasons, both hemispheres would have summer together. 3. (152 − 147) ÷ 152 is about 3%, much too small a change to cause the seasons.
• Part C: the axis is tilted and points the same way all year. In December the south leans towards the Sun, so the noon Sun is high, its light is concentrated on a small area and the days are long: summer. In June the south leans away: the light is spread out and the days are short: winter.
• Bigger: Darwin is close to the equator, so its noon Sun is high all year and its light stays concentrated.
• Exit ticket: 1. The tilt of the Earth’s axis, which changes the angle of the sunlight. 2. December. 3. At a low angle the same light is spread over a bigger area, so each square metre gets less.

Why we have seasons

A. The torch test

Hold the torch 20 cm from the paper, measured along the beam. Shine it at each angle, trace the patch and count the squares. If the torch gives 100 units of light, work out how many units fall on each square.

B. The distance idea

C. Explain it

Exit tickets

Cut into four. Students answer on their own.

Teacher note: the answers are on this lesson’s plan.

Seasons in the data

The height of the noon Sun above the horizon follows a simple rule for places south of the Tropic of Capricorn: at the equinoxes it is 90° minus the latitude; at the December solstice it is 23.4° higher, and at the June solstice 23.4° lower. Students use the rule to build a table for four Australian cities, graph it and look for patterns, then measure the Sun’s height today from the shadow of a metre ruler and a scale drawing.

We are learning to

• use a rule to calculate the noon Sun height for different places and dates,
• graph the results and describe patterns and relationships,
• measure the Sun’s height safely, from a shadow and a scale drawing.

Success criteria

• I can complete the table and explain how the latitude and the date change the noon Sun.
• I can turn a shadow length into the Sun’s height with a scale drawing.

You need

• a metre ruler or a 1 m stick, a level patch of ground in the sun, a tape measure, protractors and rulers,
• the worksheet (next sheet) and the shadow sheet (third sheet), one each per student.

Safety: the Sun’s height comes from the shadow; no one looks towards the Sun. Hats and sunscreen outside.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Do the rule, the table and the graph in Session A, and the shadow measurement in Session B, near noon if you can.

Watch for these ideas

• “The Sun is straight overhead at noon every day.” South of the Tropic of Capricorn the noon Sun is never overhead; it is always in the northern sky.
• Adding the tilt for June. In June the south leans away from the Sun, so the noon Sun is lower.
• “Hobart is colder because it is further from the Sun.” Its sunlight arrives at a lower angle and is spread more thinly.

Make it easier, make it bigger

• Easier: complete the table and the graph for Sydney and Hobart only.
• Bigger: Darwin (12.5°S) lies north of the Tropic of Capricorn. The rule gives 100.9° for its December noon Sun. What does an answer over 90° mean, and which way do shadows point?

Answers and look-fors

• Part A: Alice Springs 89.7°, 66.3°, 42.9°, 66.3°; Brisbane 85.9°, 62.5°, 39.1°, 62.5°; Sydney 79.5°, 56.1°, 32.7°, 56.1°; Hobart 70.5°, 47.1°, 23.7°, 47.1° (December, March, June, September).
• Part C: 1. The further south, the lower the noon Sun on every date. 2. In every city the noon Sun is 46.8° higher in December than in June, twice the tilt. 3. Alice Springs lies just south of the Tropic of Capricorn, so at the December solstice its noon Sun is 89.7°, almost overhead.
• Shadow sheet: angles a little below the noon value for the date if measured away from noon. The worked example: a 0.7 m shadow gives about 55°.
• Bigger: more than 90° means the Sun has passed overhead: it is 10.9° south of overhead, in the southern sky, so Darwin’s noon shadows point north in December.

Seasons in the data

The rule: noon Sun height = 90° minus the latitude at the equinoxes; add 23.4° at the December solstice; take away 23.4° at the June solstice.

A. The noon Sun in four cities

B. Graph it

Plot one line for each city, and label each line.

C. Patterns

The Sun’s height from a shadow

Stand a metre ruler upright on level ground in the sun and measure its shadow, from the foot of the ruler to the tip of the shadow. Do not look towards the Sun. Then draw it to scale: 1 m becomes 10 cm. The angle at the tip of the shadow is the Sun’s height.

A worked example (drawn smaller)

Our measurement

Our scale drawing

Tides

The Moon’s pull is stronger on the side of the Earth facing it and weaker on the far side, so the oceans stretch into two bulges, one under the Moon and one opposite. As the Earth turns, a coast passes through both, so most coasts get two high tides and two low tides a day. The Moon moves on round its orbit meanwhile, so each high tide comes about 12 hours 25 minutes after the one before: about 50 minutes later each day, like moonrise. At new and full moon the Sun and Moon pull in line and the tides have their biggest range (spring tides); at the quarters they partly cancel (neap tides). Yolŋu people of north-east Arnhem Land have long linked the tides to the Moon’s phase and position.

We are learning to

• explain why most coasts have two high tides and two low tides a day,
• read a tide table and predict the next tides,
• relate the size of the tides to the Moon’s phases.

Success criteria

• I can use the two-bulge model to explain the times in a tide table.
• I can graph sixteen days of tidal range and show where the spring and neap tides fall.

You need

• rulers and sharp pencils,
• the worksheet (next sheet) and the tide graph sheet (third sheet), one each per student.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Do the board, the tide table and the graph in Session A, and Part B in Session B.

Watch for these ideas

• “High tide is only when the Moon is overhead.” There are two bulges, so there is also a high tide when the Moon is on the far side of the Earth.
• “The tides come at the same time every day.” They come about 50 minutes later each day, like moonrise.
• “Spring tides happen in spring.” The name means the water springs up; they come twice a month, at new and full moon.

Make it easier, make it bigger

• Easier: answer Part A from day 1 only, and graph days 0 to 8.
• Bigger: the first high tide in the table is at 3:10 am on day 0. Predict the morning high tide a week later, on day 7.

Answers and look-fors

• Part A: 1. Two high tides and two low tides each day. 2. 12 h 25 min. 3. 50 minutes later. 4. 4:50 am on day 2. 5. About 6 h 12 min after high tide, halfway to the next high tide.
• Graph sheet: biggest range 2.2 m on days 0 and 15 (new and full moon: spring tides); smallest 1.0 m on days 7 and 8 (first quarter: neap tides). At new and full moon the Sun and Moon pull along the same line and their bulges add; at the quarters they pull at right angles and partly cancel. In many real ports the biggest tides come a day or two after new or full moon.
• Part B: 1. The tides are linked to the Moon: its phase sets how high the tide is, and its position at rising and setting goes with the timing; a full or new Moon brings the most water. 2. Alike: both link the tides to the Moon’s phase and position and both predict them; different: the Yolŋu account explains it with water filling the Moon, the science model with gravity. 3. Even a great scientist can be wrong; knowledge changes when new evidence and better explanations arrive, as Newton’s gravity did in 1687.
• Bigger: each day adds about 50 minutes, so seven days add about 5 hours 50 minutes: about 9:00 am.

Tides

A. A tide table

Tide times and heights for a port with two tides a day (illustrative data). Day 0 is a new moon.

B. Two ways of knowing the tides

Astronomers Ray Norris and Duane Hamacher describe how Yolŋu people of north-east Arnhem Land link the tides to the Moon. In the Yolŋu account the Moon fills with water from the sea as it rises through the horizon: a full or a new Moon carries the most water, a crescent or half Moon little. Watching the Moon’s phase and position, a Yolŋu person can predict the time and height of the next tide.

In the early 1600s the Italian scientist Galileo Galilei rejected the idea that the Moon causes tides, and explained them with the Earth’s own motion. In 1687 Isaac Newton showed that the gravity of the Moon and the Sun explains the tides.

Sixteen days of tides

The tidal range is the height of high tide minus the height of low tide. These are the daily ranges at the same port from a new moon (day 0) to a full moon (day 15).

Graph it

Plot each day’s range and join the points. The Moon’s phase, as seen from Australia, is marked above days 0, 7 and 15.

One face, and a scale model

The Moon spins once on its axis in exactly the time it takes to orbit the Earth, so the same side always faces us; the far side was first photographed by a spacecraft in 1959. Students act out the Moon’s orbit to see why it must spin to keep one face towards the Earth, then build the Earth, the Moon and the Sun to scale with a basketball and a tennis ball. The scale model shows a remarkable fit: the Sun is about 400 times wider than the Moon and about 390 times further away, so the two look almost exactly the same size in our sky, which is why the Moon can just cover the Sun in a total solar eclipse.

We are learning to

• explain why we always see the same face of the Moon,
• use a scale to build a model of the Earth, the Moon and the Sun,
• explain why a total solar eclipse is possible.

Success criteria

• I can act out the Moon’s orbit and show it turning once in each orbit.
• I can calculate the model sizes and distances from a scale, and say what the model shows that diagrams do not.

You need

• a chair, a basketball (about 24 cm across) and a tennis ball, a long tape measure or a trundle wheel, calculators,
• the worksheet (next sheet), one per student, and the exit tickets (third sheet), cut into four.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Walk the Moon and show the board in Session A, and the scale model and Part C in Session B.

Watch for these ideas

• “The Moon does not spin.” It spins once in every orbit; that is exactly why one face stays towards us.
• “The far side of the Moon is always dark.” It gets sunlight too: at new moon the far side is fully lit.
• “The Moon is quite close to the Earth.” Diagrams squeeze the distances; to scale the Moon is about 30 Earth-widths away.

Make it easier, make it bigger

• Easier: calculate only the Moon’s size and distance, and set up the two balls.
• Bigger: the Moon is moving away from the Earth by about 3.8 cm a year. How far is that in a million years, and what will it do to total solar eclipses in the far future?

Answers and look-fors

• Part A: 1. Once: the walker faced every wall in turn. 2. The chair saw every side of the walker, front, side and back. 3. Spin once in each orbit.
• Part B: Earth, diameter 24 cm; Moon, diameter 6.6 cm; Earth to Moon 725.3 cm (7.3 m); Sun, diameter 2626.4 cm (26.3 m); Earth to Sun 283 019 cm (2.8 km). The model shows how far apart the bodies are compared with their sizes: the Moon about 30 Earth-widths away, the Sun nearly 2.8 km.
• Part C: 1. 1 392 000 ÷ 3474 = about 400. 2. 150 000 000 ÷ 384 400 = about 390. 3. The Sun is about as many times further away as it is wider, so the two look almost the same size, and the Moon can just cover the Sun.
• Bigger: 3.8 × 1 000 000 = 3 800 000 cm, or 38 km. The Moon will slowly look smaller, so in the far future it will no longer cover the whole Sun, and total solar eclipses will end.
• Exit ticket: 1. It spins once in each orbit. 2. About 30. 3. It is about 390 times further away, so it looks about the same size as the Moon.

One face, and a scale model

A. Walk the Moon

B. To scale

The basketball, about 24 cm across, is the Earth, so 1 cm stands for about 530 km. Model size in cm = real size in km ÷ 530. Give long lengths in metres as well.

C. Just the right size

Exit tickets

Cut into four. Students answer on their own.

Teacher note: the answers are on this lesson’s plan.

Show what we know

The last lesson turns the term into predictions. Students use the cycles of the Earth, the Sun and the Moon to forecast the coming days: moonrise, the Moon’s shape, the tides, the chance of an eclipse and the height of the noon Sun. Then each student sits the final check on their own, and the class finishes with the unit quiz on the board.

We are learning to

• use the cycles of the Earth, the Sun and the Moon to make predictions,
• explain phases, eclipses, seasons and tides with models,
• show what we know on our own.

Success criteria

• I can make each prediction with a calculation or a reason from a model.
• I can back each answer on the final check with a model, a calculation or evidence.

You need

• the prediction task (next sheet) and the final check (third sheet), one each per student; the Lesson 2 phase cards,
• the interactive unit open for the closing quiz.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Do the task and the partner check in Session A, and the final check and the class quiz in Session B.

Watch for these ideas

• “The Moon rises at the same time every night.” Ask: what did your Moon diary show?
• “There is a solar eclipse every new moon.” Ask: what does the tilted orbit usually do to the Moon?
• “Summer comes when the Earth is closest to the Sun.” Ask: what season is it in Japan in January?

Make it easier, make it bigger

• Easier: start with task items 1, 3 and 6, with the earlier worksheets open.
• Bigger: write a prediction question about next month’s sky for a partner, with a worked answer.

Answers and marking guide

• Task: 1. About 7:00 pm: about 50 minutes later each night. 2. Last quarter, about a week after full moon: seen from Australia, lit on the right. 3. 7:30 pm today and 7:55 am tomorrow.
• Task: 4. Spring tides now, because the Sun and the Moon line up at full moon; neap tides by the end of the week, near last quarter. 5. No: a solar eclipse needs a new moon, about two weeks away, and even then the Moon usually passes above or below the line. 6. 62.5° today, 39.1° at the June solstice. 7. 58 minutes (14.4 × 4).
• Check: 1. the Earth spinning on its axis. 2. The Sun lights half the Moon; as the Moon orbits the Earth we see more or less of the lit half. 3. full moon. 4. The Northern Hemisphere has winter in January, when the Earth is nearest the Sun; or the distance changes by only about 3%.
• Check: 5. about 12.5 hours. 6. C. 7. The Moon spins once in each orbit, so the same side always faces the Earth. 8. The Sun is also about 390 times further away, so the two look almost the same size and the Moon can just cover the Sun.
• Scoring: 1 mark each for 1, 3, 5 and 6; 2 marks each for 2, 4, 7 and 8. The rubric near the front of the pack turns the task and the check into a level.

Predict the sky

Show what we know

Show what you know about the Earth, the Sun and the Moon. Read each item, then circle or write.

Teacher note: the marking guide is on this lesson’s plan; the rubric near the front of the pack turns the score into a level.