Changing Ideas About Space · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Changing Ideas About Space

Science · Space Exploration · ages 9-11
Name ______________________   Date ____________

  1. Who was the ancient thinker most linked to the geocentric model?

    • Copernicus
    • Ptolemy
    • Galileo

  2. What is the geocentric model of the solar system?

    • Earth stays still at the centre, and everything else circles around it
    • The Sun stays still at the centre, and everything else circles around it
    • Every planet moves around in its own separate space

  3. Who proposed that the Sun sits at the centre of the solar system, not Earth?

    • Ptolemy
    • Galileo
    • Copernicus

  4. True or false: in the heliocentric model, the Sun stays still while Earth moves around it.

    Circle one:   True   False

  5. What did Galileo see through his telescope that supported the heliocentric model?

    • Moons circling around Jupiter
    • Rings circling around the Moon
    • Clouds moving across the Sun

  6. Look at the timeline of ideas. Whose idea came between Ptolemy's and Galileo's telescope proof?

    PtolemyCopernicusGalileo
    • Newton
    • Copernicus
    • Aristotle

  7. Why did people believe the geocentric model for so long before Copernicus came along?

    • Because it matched what they could see: the Sun and stars seeming to move across the sky above a still Earth
    • Because Ptolemy forced everyone to agree with him
    • Because nobody had ever looked up at the sky before

  8. Milo tells you Ptolemy proved the Sun sits at the centre of everything. What is wrong with what Milo said?

    • Ptolemy lived after telescopes were invented
    • Ptolemy never studied the sky at all
    • Ptolemy actually believed Earth was at the centre, not the Sun
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Changing Ideas About Space W1-mt_KiRn5lnRgj-s1

  1. Ptolemy · Ptolemy wrote down the Earth-centred idea, and people trusted it for well over a thousand years.
  2. Earth stays still at the centre, and everything else circles around it · Geo means Earth. In this old model, Earth does not move, and the Sun, Moon, and stars circle around it.
  3. Copernicus · Copernicus proposed this heliocentric, or Sun-centred, model.
  4. True · That is exactly Copernicus's idea: the Sun stays in the centre while Earth orbits it.
  5. Moons circling around Jupiter · He saw small moons orbiting Jupiter, proving that not everything in the sky circles Earth.
  6. Copernicus · Copernicus proposed the Sun-centred idea after Ptolemy, and later Galileo found proof for it.
  7. Because it matched what they could see: the Sun and stars seeming to move across the sky above a still Earth · Without a telescope, Earth looks and feels still, so a Sun that seems to cross the sky each day was easy to believe.
  8. Ptolemy actually believed Earth was at the centre, not the Sun · Ptolemy supported the geocentric model, with Earth at the centre. Copernicus was the one who proposed a Sun-centred model.
Worksheet · LightMySky