Earth, Sun and the Day-Night Cycle: a full term of science

Ten ready-to-teach lessons for Year 6 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 or exit tickets, an assessment kit and every answer.

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, cards or tickets.
3. Gather the few everyday items under “You need” on the plan. Nothing needs a science cupboard.
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 answers are all on the one page.

No science background needed

This pack is written for the busy generalist teacher. Each plan explains the science idea in plain words, lists the misconceptions children bring, and gives model answers. The big idea of the term: Earth spins on its axis once a day, which gives day and night, and travels around the Sun once a year. Its axis is tilted and keeps the same lean all the way around, so our half of Earth leans toward the Sun in December and away from it in June. That is why our days are long in summer and short in winter, and why the pattern comes back every year. Earth is one of eight planets, each travelling around the Sun on its own path.

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 1, 3 and 9 need a room that can be darkened, Lesson 5 needs a sunny day around the middle of the day, and Lesson 6 needs a straight run on the oval for the full-scale model.

Safety and care in one look

Nobody looks at the Sun, even for a moment and never through anything; in Lesson 5 children look only at the ground. Lamps get hot, so keep hands, paper and walking paths away from the bulbs. Tape over the sharp ends of skewers. Hats on outside, and walk rather than run, both on the oval and in a darkened room.

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

Lesson 1 models the spin and Lesson 2 the lap around the Sun. Lesson 3 adds the tilt, and Lessons 4 and 5 check the model against real day lengths and noon shadows. Lesson 6 widens the view to the other planets, and Lesson 7 follows noon across Australia’s time zones. Lesson 8 sorts claims with evidence, and Lesson 9 puts the spin, the lap and the tilt into one human orrery. Lesson 10 is the explainer and the final check.

Curriculum links (Australian Curriculum V9)

The whole term teaches the Science Understanding descriptor AC9S6U02 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 6 voice.
• The assessment sheet near the front has a class observation checklist and a three-level rubric.
• Lesson 10 is the summative pair: an explainer for a Year 3 class, plus the “Show what we know” check sheet.

Materials for the whole term

One gathering session covers all ten lessons. Everything on this page is an everyday item, comes from the classroom or the school grounds, or can be borrowed; nothing needs a science cupboard. Check the forecast for a sunny day before Lesson 5, and find a straight run on the oval before Lesson 6.

The one-trip list

• From the classroom: rulers, a metre ruler, a set square, scissors, coloured pencils, A3 paper, string, tape, markers, chalk, a clock, calculators.
• From home or the shops: large balls (such as foam balls), wooden skewers, sticky dots, a table-tennis ball, a yellow hat or sign, strips of card.
• To borrow: globes (one on a tilted stand, if you can), lamps with no shade or strong torches, a trundle wheel, long tape measures, cones, a map of Australia.
• In the school grounds: a flat, sunny spot, the oval, and the hall or an open space for a circle about 6 m across.

Safety and care in one look

• Nobody looks at the Sun, even for a moment and never through anything. In Lesson 5 children look only at the shadow on the ground.
• Lamps get hot: keep hands and paper away from the bulbs, keep walking paths at least a metre away, and let an adult move a lamp.
• Tape over the sharp ends of skewers. Clear the floor and walk slowly in a darkened room.
• Hats and sunscreen for Lessons 5 and 6, and walk rather than run on the oval.

Assessment without extra work

The term assesses itself. Every lesson plan ends with answers and look-fors, and Lesson 10 is the summative pair: an explainer for a Year 3 class, and the check sheet. This sheet is the place to jot down what you notice along the way.

The three levels

Class observation checklist

A tick a lesson is plenty; the Lesson 10 check sheet fills the gaps.

Word wall cards

Cut out the cards and build the wall as the words arrive. Lesson 1 starts the wall with axis and rotation; add revolution, orbit and leap year in Lesson 2, and tilt, equator and hemisphere in Lesson 3.

Dear families

This term in science, Year 6 investigates how Earth moves. It spins on its axis once a day, which gives us day and night, and it travels around the Sun once a year. Earth’s axis is tilted, and that tilt is why our days are long in summer and short in winter. We also look at the other planets and how they travel around the Sun.

Your child will build models with a lamp and a ball, walk a lap of the Sun, count the hours of light on a tilted globe, graph a year of day lengths, measure the noon shadow of a 1 m stick, pace out the planets on the oval at their real spacing, follow noon across Australia’s time zones, and become part of a human model of the Sun and Earth. By the end of the term, they will make an explainer that teaches a Year 3 class why we have day and night and the seasons.

Try this at home

• Check the sunrise and sunset times once a week for a month; most weather apps show them. Are the days getting longer or shorter?
• Shine a torch on a ball in a dark room and turn the ball slowly. Where is it day? Where is it night?
• On a sunny weekend, stand a stick upright around lunchtime and mark the tip of its shadow every 15 minutes. When is it shortest?
• Look at a world clock on a phone. When it is dinner time here, what time is it in London?

What to ask your scientist

• What makes day and night? Can you show me with a ball and a torch?
• Why are our days longer in December than in June?
• Is Earth closer to the Sun in summer? How do you know?
• If Earth were 4 metres from the Sun, how far away would Neptune be?

A small note on care: we never look at the Sun, and lamps and torches are used with an adult nearby.

Warm regards,

The Year 6 team

Printed from the free seegongsik Earth, Sun and the Day-Night Cycle teaching pack · seegongsik.com/au/y6/earth-and-space/AC9S6U02/pack

The spinning Earth

Every morning the Sun seems to rise in the east and cross the sky to set in the west, but it is Earth that moves. Groups make a model in a darkened room: a lamp is the Sun and a ball on a stick is Earth, with Australia marked on it. As they spin the ball slowly from west to east, half of it is always lit, Australia is carried from night into day, and its east coast reaches the light before its west coast.

We are learning to

• use a model to show that Earth’s spin on its axis makes day and night,
• explain why the Sun seems to rise in the east and set in the west,
• describe one spin as one day of 24 hours.

Success criteria

• I can use the model to show day and night, sunrise and sunset.
• I can explain which side of Australia sees the sunrise first, and why.

You need

• for each group: a lamp with no shade or a strong torch, and a large ball (or a globe) with a pencil or skewer pushed through it as the axis,
• a sticky dot or a small paper flag for Australia, and a room that can be darkened,
• the worksheet (next sheet), one per child, and the exit tickets (third sheet).

Lesson flow (about 60 minutes)

Running two half-sessions instead? Build and spin the model in Session A. Start Session B with the drawing and the board.

Watch for these ideas

• “The Sun goes around Earth every day.” It only looks that way; the model shows the spinning Earth doing the moving.
• “Night is when the Sun goes behind the clouds or the Moon.” Night is our side of Earth turned away from the Sun.
• “It is night everywhere at the same time.” While Australia has night, the other side of Earth has day.

Make it easier, make it bigger

• Easier: mark only one town on the ball and stop it at day and night.
• Bigger: mark Brisbane and Perth, and work out how much later Perth reaches the light if one spin takes 24 hours and the two cities are about a tenth of a spin apart.

Answers and look-fors

• Part B: 1. the Sun can light only the half of Earth that faces it. 2. the east edge, so Brisbane sees the sunrise before Perth. 3. Earth spins from west to east, so we turn toward the Sun in the morning (it seems to rise in the east) and away from it in the evening (it seems to set in the west). 4. about 24 hours, one day.
• Bigger: about 2 hours and 24 minutes later, since a tenth of 24 hours is 2.4 hours. (Brisbane and Perth are about 37 degrees of longitude apart, close to a tenth of the way around.)
• Meeting the idea sounds like “it is day where Earth faces the Sun, and the spin carries us into the dark”.

Day and night in a model

A. Our model

B. What the model shows

Exit tickets

Cut out the tickets. Each child answers one before leaving.

Teacher note: lamps get hot; keep hands and paper away from the bulb, and never look straight at a lamp or a torch.

A year around the Sun

While it spins, Earth also travels around the Sun along a path called its orbit, and one lap is one year. Children lay twelve month cards in a big circle around a child who is the Sun, and an Earth child walks the lap, turning as they go. Back inside, they work out how many spins fit in a lap, why we have leap years, and use Earth’s distance from the Sun in January and July to test a common idea about the seasons.

We are learning to

• describe Earth’s orbit around the Sun, and one lap as one year,
• link the length of the year to leap years,
• use evidence to test the idea that distance from the Sun makes the seasons.

Success criteria

• I can say how long one spin and one lap take, and why February sometimes has 29 days.
• I can use the January and July distances to explain why distance does not make our summer.

You need

• the month cards (third sheet), cut out, and a space outside or in the hall for a circle about 6 m across,
• a yellow sign, hat or ball for the Sun child, and a ball or globe for the Earth child to carry,
• the worksheet (next sheet), one per child.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Walk the orbit and do Parts A and B in Session A. Start Session B with the distances.

Watch for these ideas

• “It is summer when Earth is closest to the Sun.” Earth is closest in early January, when it is winter in the northern half of the world.
• “The orbit is a long, stretched oval.” It is very nearly a circle; pictures drawn at a slant make it look stretched.
• “A year is exactly 365 days.” It is about 365 and a quarter, which is why a leap day is added.

Make it easier, make it bigger

• Easier: use four month cards only (January, April, July and October) and walk a quarter lap at a time.
• Bigger: find out why 2100 will not be a leap year, even though it divides by 4.

Answers and look-fors

• Part A: one spin is a day, about 24 hours; one lap is a year, about 365 and a quarter days, so Earth spins about 365 times in one lap.
• Part B: four quarters make a whole day every four years, added as 29 February. Leap years here: 2024 and 2028.
• Part C: Earth is closest (about 147 million km) in early January and furthest (about 152 million km) in early July, only about 3% further. If distance made the seasons, the whole world would have summer in January, but the northern half has winter then. So something else makes the seasons: the tilt (Lesson 3).
• Bigger: a century year is a leap year only if it divides by 400, so 2000 was a leap year but 2100 will not be.

One lap, one year

A. Spins and laps

B. Leap years

C. Is it the distance?

Earth’s distance from the Sun: early January about 147 million km; early July about 152 million km.

D. Draw the orbit

Month cards

Cut out the cards and lay them in order in a big circle around the Sun, going anticlockwise as seen from above.

Teacher note: walk slowly and keep the circle wide, away from walls and posts. The Earth child turns on the spot only every few steps, so nobody gets dizzy.

The tilt and the length of the day

Earth’s axis leans by about 23 degrees, and it keeps the same lean all the way around the Sun. Groups model what that does to the length of the day. A string marked into 24 equal parts, one for each hour of a spin, is taped around a globe or ball at our city’s distance south of the equator, and another around the equator. With the lamp as the Sun, groups count the hour marks in the light in December, March and June positions.

We are learning to

• use a model to show how Earth’s tilt changes the length of the day through the year,
• compare what a model shows with real measurements,
• explain why places near the equator have about 12 hours of daylight all year.

Success criteria

• I can count and record the hours of light in the model for three times of year.
• I can explain, with the word tilt, why our days are longer in December than in June.

You need

• for each group: a globe, or a large ball with a skewer through it as the axis and the equator drawn on; string, a ruler, a marker and tape,
• a lamp with no shade, a darkened room, and the step cards (third sheet), one set per group,
• the worksheet (next sheet), one per child.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Order the cards and set up the strings in Session A. Count and explain in Session B.

Watch for these ideas

• “The axis tilts toward the Sun, then flips back.” It keeps the same lean in space; carrying the globe around the lamp is what changes which end leans toward the Sun.
• “Summer days are longer because Earth spins slower.” Every spin takes the same 24 hours; more of our line is in the light.
• “The model must match the real numbers exactly.” Hand-marked strings and a nearby lamp make a model a little out; the pattern is what matters.

Make it easier, make it bigger

• Easier: count the December and June positions only, on our line only.
• Bigger: add a third string near the South Pole and predict, then count, what happens there in December and in June.

Answers and look-fors

• Step cards in order: B, D, F, A, E, C.
• Part A: counts vary. Usually, on our line, more than 12 marks are lit in December, about 12 in March and fewer than 12 in June; the equator string has about 12 lit marks in every position.
• Part B (Melbourne): December about 14.8 hours, March about 12.4 hours, June about 9.6 hours.
• Part C: the axis keeps the same tilt, so in December the south leans toward the Sun and more of each spin is in daylight; in June it leans away, so less is. With no tilt, every place would get 12 hours all year.

Counting the hours of light

A. Our counts: hour marks in the light

B. The real numbers

Hours of daylight in Melbourne on the 15th of the month: December 14.8, March 12.4, June 9.6.

C. Explain it

Step cards

Cut out the cards and put them in the order you will do them. Check the order with your group before you start.

Teacher note: keep the axis pointing the same way in the room as the globe moves around the lamp. Lamps get hot; keep hands and paper away from the bulb.

A year of day lengths

The model in Lesson 3 predicted long December days and short June days. Here is the real pattern: the hours of daylight on the 15th of every month for three cities, from Darwin in the tropics to Hobart in the far south. Children graph two of the cities, find when the days are longest and shortest, and discover that the further a city is from the equator, the bigger the change through the year.

We are learning to

• draw a line graph of a pattern that repeats each year,
• describe how day length changes through the year and from place to place,
• link the pattern to Earth’s tilt and its trip around the Sun.

Success criteria

• I can find the longest and shortest days on the graph and work out the change in hours.
• I can describe how the change depends on how far a city is from the equator.

You need

• the worksheet (next sheet), one per child, two coloured pencils each, and the exit tickets (third sheet),
• a map of Australia, and the interactive unit on the board.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Graph in Session A. Start Session B with the pattern and Hobart.

Watch for these ideas

• “Darwin’s line is flat, so Darwin has no seasons.” Its day length changes a little; its seasons are wet and dry rather than hot and cold.
• “The longest day is in January because January is hottest.” The longest day is in December; the warmest weeks often come after it.
• Joining the December dot back to January as if the year stops. The pattern carries on into the next year.

Make it easier, make it bigger

• Easier: plot Melbourne only, using every second month.
• Bigger: find the hours of daylight for your own town on the Bureau of Meteorology website, and add it to the graph.

Answers and look-fors

• Part C: 1. Melbourne’s longest day is in Dec (14.8 hours) and its shortest in Jun (9.6 hours), a change of 5.2 hours. 2. Darwin changes by 1.5 hours (11.4 to 12.9) and Hobart by 6.3 (9 to 15.3).
• 3. The further a city is from the equator, the bigger the change in day length through the year. 4. Earth goes around the Sun once a year, and its tilt leans the south toward the Sun in December and away in June every year, so the pattern repeats.
• Both lines cross 12 hours near March and September, when neither half of Earth leans toward the Sun.

Long days, short days

A. Hours of daylight on the 15th of each month

B. Our graph

Plot Melbourne and Darwin, one colour each, and join each set of dots.

C. The pattern

Exit tickets

Cut out the tickets. Each child answers one before leaving.

Teacher note: these hours are worked out from the Sun’s position for each city and match published sunrise and sunset tables to within a few minutes.

The noon shadow through the year

The Sun is highest in the sky around the middle of the day, and that is when a shadow is shortest. But how high the Sun climbs changes through the year, because of the tilt. The class measures the shadow of a 1 m stick every 20 minutes around the middle of the day to find today’s shortest shadow, then graphs a year of noon shadows for Melbourne and explains the pattern.

We are learning to

• measure a shadow carefully and find the shortest one of the day,
• graph and describe how the noon shadow changes through the year,
• explain the pattern with the height of the Sun and Earth’s tilt.

Success criteria

• I can say when today’s shadow was shortest and how long it was.
• I can explain why the noon shadow is short in December and long in June.

You need

• a metre ruler or a 1 m stick held upright (check it with a set square or a book corner), a tape measure and chalk,
• a flat, sunny spot, a clock, and a sunny day,
• the worksheet (next sheet), one per child, and the exit tickets (third sheet).

Lesson flow (about 60 minutes)

Running two half-sessions instead? Measure outside in Session A, around the middle of the day. Graph and explain in Session B.

Watch for these ideas

• “The shortest shadow is always at 12 o’clock.” Daylight saving and where your town sits in its time zone move it, often towards 1 pm.
• “The Sun is straight overhead at noon.” Not in southern Australia: even in December the noon shadow does not disappear.
• “A longer shadow means the Sun is further away.” It means the Sun is lower in the sky.

Make it easier, make it bigger

• Easier: measure only at 12:00, 1:00 and 1:40 and find the shortest of the three.
• Bigger: mark the direction of the shortest shadow with chalk. Which way does it point? (South.)

Answers and look-fors

• Part A: readings vary with the date and your town; the shortest shadow is the noon one.
• Part C: 1. shortest in Dec (about 26 cm), longest in Jun (about 181 cm). 2. about 7 times as long. 3. in December the south leans toward the Sun, so the noon Sun climbs high and the shadow is short; in June the south leans away, so the noon Sun stays low and the shadow is long.
• Bigger: in southern Australia the noon Sun is to the north, so the shortest shadow points south.

The shortest shadow

A. Today’s shadows of a 1 m stick

B. Melbourne’s noon shadow of a 1 m stick, on the 15th of each month

C. Explain it

Exit tickets

Cut out the tickets. Each child answers one before leaving.

Teacher note: never look at the Sun, even through the stick’s shadow line; look only at the ground. Other towns’ noon shadows differ a little from Melbourne’s, but the pattern is the same.

The planets: a scale model

Earth is one of eight planets travelling around the Sun, and pictures of them nearly always squeeze them together to fit the page. Here the class builds a model with the real spacing. One unit, the distance from the Sun to Earth (about 150 million km), becomes 4 m on the oval. Children work out where each planet goes, put the planet cards in order, then pace out the solar system from a Sun the size of a table-tennis ball.

We are learning to

• use a scale to build a model of the distances in the solar system,
• describe the order of the planets and how far apart they are,
• find the pattern between a planet’s distance from the Sun and the length of its year.

Success criteria

• I can use the scale to work out where a planet goes on the model.
• I can explain why a planet further from the Sun has a longer year.

You need

• a trundle wheel or a long tape measure, nine cones or markers, and a straight run of about 125 m on the oval,
• a table-tennis ball for the Sun and a grain of sand for Earth; calculators (optional),
• the worksheet (next sheet), one per child, and the planet cards (third sheet), one set for the class.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Work out the scale and order the cards in Session A. Pace it out and answer Part C in Session B. Short of space? Use 1 unit = 2 m and halve every distance (Neptune at 60.2 m).

Watch for these ideas

• “The planets are close together, like in the pictures.” Pictures squeeze them to fit; on our model Neptune is 120.4 m from the Sun and Earth is a grain of sand.
• “The closer a planet is to the Sun, the hotter it is.” Venus is hotter than Mercury, because its thick air traps the heat.
• “Every planet spins once in 24 hours, like Earth.” Each has its own spin: Jupiter takes about 10 hours, Venus about 243 Earth days.

Make it easier, make it bigger

• Easier: model the four planets closest to the Sun only, in the classroom or a corridor (Mercury 1.6 m to Mars 6.1 m).
• Bigger: how old would you be on Mars? Turn your age into days and divide by 687.

Answers and look-fors

• Part A: Mercury 1.6, Venus 2.9, Earth 4, Mars 6.1, Jupiter 20.8, Saturn 38.3, Uranus 76.8, Neptune 120.4 m. Part B, cards in order from the Sun: F, B, H, D, A, G, C, E.
• Part C: 1. Mercury, Venus, Earth and Mars are all within 7 m of the Sun; Mars to Jupiter is 14.7 m. 2. empty space. 3. the longer its year: it has further to go, and it moves more slowly. 4. Venus takes longer to spin once than to go around the Sun.
• On this model the Sun is a ball about 3.7 cm across, Earth 0.34 mm (a grain of sand) and Jupiter about 3.7 mm (a peppercorn). Bigger: an 11-year-old has lived about 4,015 days, about 5.8 Mars years.

The solar system on our oval

A. Our scale

1 unit is the distance from the Sun to Earth, about 150 million km. On our model, 1 unit = 4 m. Multiply by 4 and round to one decimal place.

B. The order

C. What the model shows

Planet cards

Cut out the cards. Write each planet’s distance on our model on its card, then carry the card to its place on the oval.

Teacher note: hats on outside, and walk the distances rather than run. Keep the line straight and away from goalposts and fences.

Time zones: noon travels west

Earth turns all the way around, 360 degrees, in 24 hours, so it turns 1 degree every 4 minutes. The moment the Sun is highest in the sky, its noon, sweeps from east to west across Australia. Children work out from each city’s longitude how many minutes after Brisbane the Sun is highest there, make a human map of the cities, then compare the Sun’s noon with what the clocks say in our three time zones, in winter and in daylight saving time.

We are learning to

• explain why the Sun is highest in eastern places first,
• use Earth’s spin to work out how much later noon reaches a place further west,
• explain why Australia has time zones and how daylight saving changes the clocks.

Success criteria

• I can work out how many minutes after Brisbane the Sun is highest in another city.
• I can read the clock time in another city when it is noon in Sydney, in winter and in summer.

You need

• the city cards (third sheet), one set, a measuring tape, and a sign that says NOON,
• a map of Australia, and calculators (optional),
• the worksheet (next sheet), one per child.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Work out Part A and make the human map in Session A. Start Session B with the clocks.

Watch for these ideas

• “When it is noon here, it is noon everywhere.” Noon moves west about 4 minutes for every degree, and on the far side of Earth it is midnight.
• “Daylight saving gives us an extra hour of daylight.” The day is just as long; the clocks move forward, so more of the daylight comes in the evening.
• “The clock says 12, so the Sun must be highest.” A whole time zone shares one clock, so in most towns the Sun is highest a little before or after 12.

Make it easier, make it bigger

• Easier: work out Part A for Brisbane, Melbourne and Perth only.
• Bigger: a cricket match starts at 7 pm in Perth in December. What time is it in Sydney?

Answers and look-fors

• Part A: Brisbane 0; Sydney 1.8° and 7 min, Hobart 5.7° and 23 min, Melbourne 8° and 32 min, Adelaide 14.4° and 58 min, Darwin 22.2° and 89 min, Perth 37.1° and 148 min. The order: B, F, D, G, A, E, C. Human map: Sydney 18 cm, Hobart 57 cm, Melbourne 80 cm, Adelaide 144 cm, Darwin 222 cm, Perth 371 cm.
• Part B, June: Brisbane, Hobart and Melbourne 12:00; Adelaide and Darwin 11:30; Perth 10:00. December: Hobart and Melbourne 12:00; Adelaide 11:30; Brisbane 11:00; Darwin 10:30; Perth 9:00.
• Part C: 1. they are in the same time zone and both use daylight saving; one clock across a whole zone makes travel, TV times and phone calls simpler, even though the Sun is highest about 25 minutes later in Melbourne. 2. five different times. 3. Earth spins from west to east, so the east turns to face the Sun first. Bigger: 10 pm, since Perth is 3 hours behind Sydney in summer.

Noon travels west

A. When is the Sun highest?

Earth turns 1 degree every 4 minutes. For each city, work out how many degrees west of Brisbane it is, then how many minutes after Brisbane the Sun is highest there. Round to the nearest minute.

B. The clocks when it is noon in Sydney

Eastern time: Queensland, New South Wales, the ACT, Victoria and Tasmania. Central time, half an hour behind eastern time: South Australia and the Northern Territory. Western time, 2 hours behind eastern time: Western Australia. In daylight saving (October to April), New South Wales, the ACT, Victoria, Tasmania and South Australia move their clocks 1 hour forward; Queensland, the Northern Territory and Western Australia do not.

C. Explain it

City cards

Cut out the cards. Work out where each city stands on the human map: 10 cm west of Brisbane for every degree west of Brisbane.

Teacher note: the longitudes are rounded to a tenth of a degree. A few towns keep a different clock from the rest of their state; Broken Hill in New South Wales, for one, keeps central time.

True or not true?

People say all sorts of things about the seasons and the sky, and some of them sound right but are not. Groups sort nine claim cards into two piles, true and not true, with one rule: no card goes in a pile without evidence from this term, such as a model we built, a measurement we made or a fact we checked. Then children rewrite two claims that are not true so that they are, and write a claim of their own for a partner to sort.

We are learning to

• decide whether a claim is true by checking it against evidence,
• select evidence from models and measurements to support a conclusion,
• correct a claim that is not true, using science words.

Success criteria

• I can sort a claim and name the evidence that decided it.
• I can rewrite a claim that is not true so that it is true.

You need

• the claim cards (third sheet), cut out, one set per group of three,
• the worksheets from Lessons 1 to 7, and a globe and lamp from Lesson 3 for testing claims,
• the worksheet (next sheet), one per child, and a strip of card per child for Part C.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Sort with evidence in Session A. Start Session B by settling the arguments.

Watch for these ideas

• “It sounds right, so it is true.” Card C sounds sensible; the January distance from Lesson 2 shows it is not.
• “Not true means the opposite is true.” For card C, “summer is hot because Earth is further away” is not true either: distance is not the cause; the tilt is.
• “The South Pole is dark all year.” It has months of darkness around June and months of sunlight around December, when the Sun never sets there.

Make it easier, make it bigger

• Easier: tell each group which lesson holds the evidence for each card.
• Bigger: find the Tropic of Capricorn on a map of Australia. Which capital city can have the Sun straight overhead at noon?

Answers and look-fors

• True: A, B, E, G and I. Not true: C, D, F and H.
• A (true): Early January is when Earth is closest, but only about 3% closer than in July.
• B (true): In June the south leans away from the Sun, so near the pole it stays dark for months.
• C (not true): Earth is closest in January, when it is winter in the northern half of the world: the tilt, not the distance, makes the seasons.
• D (not true): The longest day is around 21 or 22 December, when the south leans toward the Sun.
• E (true): Places near the equator stay close to 12 hours all year; the further south, the bigger the change.
• F (not true): Melbourne is too far south: even in December the noon Sun is about 14 degrees from straight up. Of the capital cities, only Darwin, north of the Tropic of Capricorn, ever has it overhead.
• G (true): Then neither half of Earth leans toward the Sun, so day and night are close to equal.
• H (not true): The axis keeps the same lean in space; Earth moving around the Sun changes which half leans toward it.
• I (true): Earth spins from west to east, so the east side turns to face the Sun first.
• Part B: for example, “Summer is hot because our half of Earth leans toward the Sun then, so the Sun climbs higher and the days are longer.” Bigger: Darwin.

Sort it with evidence

A. True or not true?

For each card, circle T (true) or N (not true), then write the evidence that decided it: a model, a measurement or a fact from our lessons.

B. Fix it

C. Make a claim card

Claim cards

Cut out the cards. Sort them into two piles, true and not true. No card goes in a pile until your group agrees on its evidence.

Teacher note: keep a spare set of cards for groups that want to re-sort after the class discussion.

The human orrery

An orrery is a working model of the solar system. Here the class becomes one, putting the spin, the lap and the tilt into a single model. A lamp in the middle of the room is the Sun. An Earth child carries a tilted globe anticlockwise around it, past four season signs, keeping the North Pole leaning toward the same wall all the way. At each sign the globe is spun once, and the class watches how much of the spin Australia spends in the light.

We are learning to

• use one model to show how the tilt, the spin and the lap work together,
• explain why the tilt that never changes still gives us summer and winter,
• compare what the model shows with real day lengths.

Success criteria

• I can say which pole leans toward the Sun at each stop, and what that does to our day.
• I can explain why the same lean gives long days in December and short days in June.

You need

• a lamp with no shade on a chair in the middle of the room, a room that can be darkened, and space for a circle about 4 m across,
• a globe on a tilted stand (or the ball and skewer from Lesson 3) with Australia marked,
• the orrery signs (third sheet), the month cards from Lesson 2, and the worksheet (next sheet), one per child.

Lesson flow (about 60 minutes)

Running two half-sessions instead? Set up and run the orrery in Session A. Check and explain in Session B, with one quick lap to remind everyone.

Watch for these ideas

• “The Earth child should keep the South Pole pointing at the lamp.” Then it would be summer all year. The lean keeps pointing the same way in the room.
• “In March and September the axis is not tilted.” It is tilted just as much; it leans sideways to the Sun, neither toward it nor away.
• “Going around the Sun makes day and night.” The spin makes day and night; the lap with the tilt makes the seasons.

Make it easier, make it bigger

• Easier: run the orrery at the December and June stops only.
• Bigger: at which stop does the South Pole stay in the dark for the whole spin? What does that mean for the people who work there?

Answers and look-fors

• Part A: December, the South Pole leans toward the Sun, our day is more than 12 hours; March, neither pole leans toward the Sun, our day is about 12 hours; June, the North Pole leans toward the Sun, our day is less than 12 hours; September, neither pole leans toward the Sun, our day is about 12 hours.
• Part B: Melbourne’s real day lengths in hours: 21 December about 14.8, 21 March about 12.2, 21 June about 9.5, 23 September about 12.2. The longest day is in December and the shortest in June. The March and September days are a little over 12 hours, because daylight counts from when the top of the Sun first shows and the air bends its light over the horizon.
• Part C: 1. the axis keeps the same lean in space; carrying Earth to the other side of the Sun turns the leaning South Pole away from it. 2. every place would have about 12 hours of daylight all year. Bigger: June; the South Pole has months of darkness then, and people working there live by the clock and electric light.

Our orrery

A. At each stop

B. The real numbers

Hours of daylight in Melbourne: 21 December about 14.8, 21 March about 12.2, 21 June about 9.5, 23 September about 12.2.

C. Explain it

Orrery signs

Cut out the signs. Stick the wall sign on one wall, and put each month sign on the floor by its month card.

Teacher note: lamps get hot, so keep the path at least a metre from the lamp. Clear the floor and walk slowly in the dark.

Show what we know

The summative lesson, run as a celebration. Each child, or pair, makes an explainer for a Year 3 class: a poster or a labelled model that shows why we have day and night, why a year is a year, and why our days are long in December and short in June. Pairs try their explainers on each other as if they were Year 3s, everyone sits the final check alone, and the class closes with the on-screen quiz as a game.

We are learning to

• explain how Earth’s spin, its trip around the Sun and its tilt make day and night, the year and the change in day length,
• choose words, pictures and evidence that suit a younger audience,
• show what we know on our own on the final check.

Success criteria

• My explainer shows the spin, the lap and the tilt, with one number from our lessons as evidence.
• I can show on the final check how Earth’s movements make day and night and the changing length of the day.

You need

• A3 paper and coloured pencils, or a ball, a skewer and a torch for a model; the worksheets from Lessons 1 to 9 for evidence,
• the explainer planning sheet (next sheet) and the final check (third sheet), one each per child,
• the interactive unit open for the closing quiz.

Lesson flow (about 60 minutes)

Running two half-sessions instead? End Session A after making the explainers. Start Session B with the try-out, then the final check and the class quiz. If you can, book a visit to a Year 3 class to share the explainers for real.

Watch for these ideas

• An explainer where the tilt swaps sides through the year. Ask: does the lean change, or where Earth is?
• The spin and the lap mixed up: “Earth goes around the Sun every day.” Ask: which movement takes 24 hours?
• Distance as the cause of summer. Ask: if being closer made summer, when would the northern half have its summer?

Make it easier, make it bigger

• Easier: make the explainer about day and night and the year only, using the orrery picture from Lesson 9.
• Bigger: add a part that explains why Darwin’s day length hardly changes, or why Mars has seasons too.

Answers and look-fors

• Final check marking guide: 1 Earth spinning on its axis. 2 one lap is a year, about 365 and a quarter days; one spin is a day, about 24 hours. 3 December. 4 the axis keeps its tilt, and in December our half of Earth leans toward the Sun, so more of each spin is in daylight; in June it leans away. 5 Darwin. 6 in early January it is winter in the northern half of the world, so distance cannot be the cause; the tilt is. 7 10 am; Perth is further west, so the Sun reaches it later, and Western Australia’s clocks are 2 hours behind. 8 any planet from Mars outward, such as Mars (687 Earth days): longer, because it has further to go and moves more slowly.
• A score of 6 or more out of 8, plus an explainer that shows the spin, the lap and the tilt with evidence, meets the descriptor. The rubric near the front of the pack turns this into a level.
• Meeting the idea sounds like “the tilt never changes, but as Earth goes around the Sun our half leans toward it in December, so we get long summer days, and away from it in June”.

My explainer for a Year 3 class

My explainer will be a:   poster   /   model   (circle one)

Sketch the tilt

Show what we know

Show what you know about Earth, the Sun and the day-night cycle. Read each one, then circle or write. Take your time.

Teacher note: read the items aloud one at a time. The marking guide is on this lesson’s plan; the rubric near the front of the pack turns the score into a level.