
Suitable For
Grade 4
Difficulty
2
Time Required
<1 Hour
Supervision
Advised
What’s it about?
Astronomy is the scientific study of celestial objects (such as stars, planets, comets, nebulae, star clusters and galaxies) and other phenomena that originate outside the Earth’s atmosphere. Astronomers are very clever people and they can tell us a lot about the heavenly bodies around us.
They tell us that the moon’s diameter is only about one quarter of the size of the earth’s diameter, but in turn the Sun’s is more than one hundred times bigger in diameter than the earth. The moon is approximately 380,000 km from the earth and the sun is about 1,500,000,000 km away from the earth. It is very difficult to interpret and understand what these distances mean, but the following science experiment should shed some light on the above:
Topics covered
Celestial objects
What will I need?
- PENCIL
- STIFF PAPER
- A PAIR OF COMPASSES
- A FRIEND
Procedure (Method)
Astronomy is the scientific study of celestial objects (such as stars, planets, comets, nebulae, star clusters and galaxies) and other phenomena that originate outside the Earth’s atmosphere. Astronomers are very clever people and they can tell us a lot about the heavenly bodies around us. They tell us that the moon’s diameter is only about one quarter of the size of the earth’s diameter, but in turn the Sun’s is more than one hundred times bigger in diameter than the earth. The moon is approximately 380,000 km from the earth and the sun is about 1,500,000,000 km away from the earth. It is very difficult to interpret and understand what these distances mean, but the following science experiment should shed some light on the above:

- Draw a circle, using a pair of compasses or a stencil, of 4 mm in diameter on a piece of stiff paper. This circle will represent the earth.
- Measure about 120mm away from the earth and draw a dot of approximately 1mm in size. This dot represents the moon in its correct size and distance away from the earth.
- Now, on a new larger piece of card or stiff paper, draw a circle of 440 mm in diameter with the pair of compasses. You may want to colour it in using paint or crayons for better visibility from afar. This will be the sun for this experiment, and is on the same scale as the earth and the moon drawn on the other card.
- Ask your friend to take one of the pieces of card with the ‘sun’ celestial body drawn on it, and then walk 44 metres away from you whilst holding up the card with sun on it.
- You may now also hold up your card with the earth and moon on it. The Earth, moon and sun are now in scale in both size and distance from each other. Can you believe how far the sun is from the earth?