Year 5 · Autumn 1.2 · Step 5

Earth & Space

The Solar System: ideas over time

From Earth at the centre to the Sun at the centre — how evidence changed what scientists believed.

Arrival Starter I do We do Independent Exit ticket
🌱 Seedling · Working towards 🌿 Sapling · Expected 🌳 Oak · Greater depth

⏱ Whole lesson ≈ 44 min · pick a tier in the bar, or leave on "All"

Arrival 4 min

Whiteboard recap of last lesson: motion and gravity.

Recap: motion & gravity

🌱 Seedling
Working towards

Fill the gaps:

Planets orbit the ___ · the Sun's ___ holds them in orbit
🌿 Sapling
Expected
  1. Why do planets stay in orbit?
  2. Which planet orbits fastest?
  3. What does "heliocentric" mean?
🌳 Oak
Greater depth

Explain why different planets have different length years.

Bridge into todayWe say the Sun is at the centre. But long ago, people were sure the Earth was. Today: how did that idea change?
Starter 5 min

Ask: from where you stand, does it look like the Sun moves round the Earth?

Trust your eyes?

Enquiry question: How have ideas about the Solar System changed over time?

🌱 Seedling
Working towards

True or false: the Sun goes round the Earth. Why might someone think that?

🌿 Sapling
Expected

Why did people long ago believe the Earth was at the centre? Give a reason.

🌳 Oak
Greater depth

What would you need to prove that the Earth goes round the Sun, not the other way?

I do · 1 6 min

Teacher models. Watch how the idea changed.

From Earth-centred to Sun-centred

▶ Can't see it? Watch "The Heliocentric Model | Year 5 Earth & Space" on YouTube

Swap the clip: change the ID after /embed/ (now -ryMxue-cEQ).

Say thisLong ago, Aristotle and Ptolemy taught the geocentric model — Earth at the centre. Later, Copernicus argued for the heliocentric model — the Sun at the centre. Galileo found evidence with a telescope, and Newton explained it with gravity.
🌍
GeocentricEarth centre
☀️
HeliocentricSun centre
🔭
EvidenceGalileo, Newton
We do · 1 6 min

Match each scientist to their idea.

Who thought what?

Aristotle · Ptolemy · Copernicus · Galileo · Newton

Reason it out
Earth at the centre → geocentric. Sun at the centre → heliocentric. Gathered proof → used new evidence.
"Copernicus said the Sun was at the centre — that is the heliocentric model."
I do · 2 4 min

Play the animation. Watch the centre change.

The great switch

Earth Geocentric: Earth at the centre Sun Heliocentric: Sun at the centre

Ideas changed: from Earth at the centre to the Sun at the centre.

Bust the mythsPeople once thought the Earth was flat and at the centre — both wrong. We now know Earth is spherical and the Sun is at the centre, with the planets orbiting it.

Watch for: pupils thinking older scientists were "silly" — they used the best evidence they had at the time.

We do · 2 5 min

Compare the two models together.

Geocentric vs heliocentric

Compare
Same: both try to explain the sky. Different: what sits at the centre — Earth or the Sun.
Science changed its mind because new evidence (like Galileo's telescope) showed the Sun-centred model fit better.
Independent 10 min

On your own. Sort each card, then answer the big question.

Ideas over time sorter

🌍 Geocentric

☀️ Heliocentric

🔭 Used new evidence

Tap a card to sort it…

🌱 Seedling
Working towards

Sort the cards. Then finish: The ______ model puts the Sun at the centre.

🌿 Sapling
Expected

Sort them, then answer the enquiry question in one sentence: how did ideas change?

🌳 Oak
Greater depth

Sort them, then explain why the idea changed — what did Galileo and Newton add?

Exit ticket 4 min

Answer at your tier, then hand it in.

Show what you know

🌱 Seedling
Working towards
  • Geocentric = ____ at the centre.
  • Heliocentric = ____ at the centre.
🌿 Sapling
Expected
  1. Who suggested the Sun was at the centre?
  2. What did Galileo use to gather evidence?
  3. Which model is correct?
🌳 Oak
Greater depth

Answer the enquiry question: how — and why — have ideas about the Solar System changed over time?

🧭 Coming nextWe know Earth orbits the Sun. Next we zoom in on our own planet and how it spins.
TA Focus · Ideas over time
Traps to watch

Myths: Earth is flat, and Earth is at the centre — both were once believed, both are wrong. Emphasise that older scientists used the best evidence they had; science updates as evidence grows.

Tier steer
Always

Geo = Earth centre · Helio = Sun centre · evidence changes ideas.

Cold Call · Question bank
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