Year 7 Science · Unit 4 · Lesson 7

Models of the Solar System

Master Worksheet

Name

Date

Class

Learning Goals

Read a timeline of evidence and explain how the model changed over time.
Decide whether each piece of evidence supported the old or the new model.
Evaluate why changing a model with evidence is a strength of science.

Warm Up

Read the timeline

Study the timeline of how our model of the Solar System changed. Then answer the question below it.

In your own words, describe what the timeline shows about how the model of the Solar System changed between 150 CE and the 1600s.

Go Deeper

Sort the evidence

Each observation below was either easier to explain with the geocentric (Earth-centred) model or with the heliocentric (Sun-centred) model. Tick the model it best supports, then give a short reason.

Observation	Geocentric?	Heliocentric?	Reason
The Sun appears to cross the sky each day
Four moons clearly orbit Jupiter, not the Earth
Venus shows a full set of phases like the Moon
Planets move in slightly stretched ovals, not perfect circles

(a) Using the table above, explain why the heliocentric model gradually replaced the geocentric model. Refer to at least two pieces of evidence.

Challenge 4 marks

(b) The geocentric model was not simply thrown away in a single day. Explain how the model was first modified and then rejected as more evidence arrived.

Challenge 3 marks

(c) Evaluate this statement: "A scientific model that changes must have been bad science in the first place." Do you agree? Justify your answer using the story of the Solar System.

Challenge 4 marks

Wrap Up

In one sentence, what was the main idea of this lesson?