SNC 1D1
A Model of the Solar System
Scaling the distances
An Astronomical Unit (AU) is equal to Earth’s average distance from the sun (150 million km). To find the
distance of other planets from the sun in astronomical units divide their distance from the sun by Earth’s
distance. Example for Mercury: 57.9/150 = 0.39
Procedure:
1. Fill in the average distances from the sun using Table 2 on page 319.
2. Divide each distance by Earth’s distance from the sun
Object
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Average Distance
From the Sun
(million km)
Scaled Distance from
the Sun
(1 AU=1cm)
57.9
0.39 cm
150
Scaling the diameters
In order to compare the Earth’s diameter to other planet’s diameters we are going to change each planet’s
diameter to be relative to the Earth’s. To do this we divide each diameter by the Earth’s diameter of 12750
km. For example for mercury 4880 km /12750 km = 0.382. This means that mercury is 0.38 times the size of
Earth. Diameters of each planet are on page 319.
Procedure:
1. Fill in the actual diameters using Table 2 on page 319. 2. Divide each diameter by Earth’s diameter
Object
Sun
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Actual Diameter
(km) of object
Diameter relative to
Earth’s Diameter
1392000
4880
12750
1 mm
Diameter
Page 2
A Model of the Solar System
Part 1: Creating your model
Instructions:
Marking Scheme:
Table 1
Table 2
Planet sizes
Planet locations
Planets coloured/
labelled
C Total:
TI Total:
C
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1. Tape two pieces of white paper together (tape only on the back)
2. Since the sun is 109 times larger than the Earth’s diameter, if we let the
Earth’s diameter be 1 mm, the Sun’s diameter would be 109 mm, which
is equal to approximately 11 cm. Use a compass to draw the sun, to
scale, at one end of the paper. When you use a compass you must set it
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up for ½ of the diameter. (5.5 cm)
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For a bonus mark copy the marking scheme in the box onto the top right
corner of your model of the solar system
3. Draw a straight line down the middle of both pieces of paper starting at your sun.
4. Use the data you calculated in column 3 of your 1st table and a
ruler to measure the positions of the eight planets from the Sun.
Let 1 cm represent 1 AU. (the first 3 planets will all be
within 1 cm of the sun). Mark each position with a small dot.
5. Draw each planet to scale at its correct distance from the sun using
the information in column 3 of table 2. Let 1 mm represent 1 Earth Diameter. If a planet’s
scale diameter is 1 mm or less it will just be a small dot.
6. Label each planet and then use pencil crayons to lightly shade in the planets (where possible). Try to
pick appropriate colours.
7. Put a title at the top (Scale Model of the Solar System) of the page and your name and date in the far
right corner.
Part 2: Thinking & Inquiry Questions (9 marks)
Answer the following questions on the back of your solar system model. Use full sentences!
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i. From your model what do you notice about the distance between the terrestrial planets compared
with the spacing between the gas giants?
ii. The closest star to our Sun is Proxima Centauri. It is approximately 268 000 AU away from the
Sun. How far away would this be from the Sun in your scale model? Convert your answer to km.
There are 100 cm in a metre and 1000 metres in a km so therefore there are 100 000 cm in a kilometre.
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iii. In your scale model, how does the size of Jupiter compare to the size of the Sun? Estimate how
many Jupiters would fit across the diameter of the Sun. Then measure to see if you were correct.
iv. Your model showed the eight planets lined up in a row. What is one advantage and disadvantage
of doing this?
v. What are the advantages of expressing distances in astronomical units rather than in kilometres?