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Name ________________________________
Partners ______________________
Stars Above, Earth Below
By Tyler Nordgren
Laboratory Exercise for Chapter 4
Equipment: Meter stick, surveying flags (on each flag tape one of the “planets” found
at the end of the lab)
SCALE MODEL SOLAR SYSTEM
Purpose:
To make a model of our solar system where the size of the planets and their
distances from one another and the Sun are accurate and to the same scale.
Introduction
Have you ever looked at a road map while on a long car trip? On the map the dot marking
LA and the dot marking New York City are 27 inches apart. In reality we know that the
two cities are not actually 27 inches apart. But we do know that the map is to scale. What
this means is that we can trust that every inch shown on the map corresponds to some
number of miles in real life. This is the map’s scale and is usually shown by a bar in the
corner somewhere. For the map I’ve described above, the scale says that 1 inch = 100
miles (scale = 100 miles/inch). If the two cities are 27 inches apart on the map then they
are 2700 miles apart in reality. We are going to make a scale map (or model) of our solar
system.
The solar system is defined as the whole collection of planets, moons,
asteroids, and comets that orbit our Sun, a star. Since the name of our star
is Sol, the collection of things orbiting it is the solar system.
Instructions
I would like the Sun in our model to be the size of a large orange or grapefruit: 5 inches
in diameter. We will now determine how big our model will need to be in order for the
Sun to be an orange.
1. Before we calculate anything, how big of a solar system do you think this model
will be if the Sun is going to be the size of an orange? Will this model of the solar
system fit (pick the closest):
a. Inside the classroom?
b. Inside the building?
c. Inside the boarders of campus?
d. Inside the city?
Stars Above, Earth Below
Scale Model Solar System
Page 2
e. Inside the state?
STOP now and discuss your guess with the class.
2. A big orange is about 5 inches in diameter. If the sun is really 1,392,000 km in
diameter, what will the scale of this solar system model be in km/inch? In other
words, every inch we measure will represent how many kilometers in the solar
system?
Scale = _________________________ km/inch
3. We now need to shrink each of the planets by this amount. On Table 1, calculate
the diameter of each planet in inches based on the scale you just found. If you’ve
done everything correctly you should get the same diameter for the Sun as you
started with: 5 inches.
4. Now let’s check your answer to Question 1: How big is this scale model? If it’s
too big to walk it won’t be practical for us to make. On the bottom half of the
same table as before, calculate the distance between the Sun and each of the
planets. Since the distance expressed in inches will be a large number, express
each distance in yards (36 inches = 1 yard). NOTE: the number given for each
planet’s distance is in millions of kilometers.
Stop here until everyone is ready.
Stars Above, Earth Below
Scale Model Solar System
Page 3
Table 1: The size and distances of the planets.
Planet
Sun
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Planet
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Diameter
(km)
1,392,000
4,880
12,100
12,800
6,800
142,800
120,000
52,000
49,500
2300
Distance
(x106 km)
58
108
150
228
778
1,427
2,871
4,497
5,914
Scaled Diameter
(inches)
Scaled Distance
(yards)
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Scale Model Solar System
Page 4
Answer Key
Planet
Sun
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Planet
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Diameter
(km)
1,392,000
4,880
12,100
12,800
6,800
142,800
120,000
52,000
49,500
2300
Distance
(AU)
0.4
0.7
1
1.5
5.2
9.5
19.1
30.1
39.5
Scaled Diameter
(inches)
5 - orange
.02 – poppy seed
.04 - sprinkle
.04 - sprinkle
.02 – poppy seed
.5 - skittle
.4 - skittle
.19 – pepper corn
.18 – pepper corn
.01 – poppy seed
Scaled Distance
(yards)
6
10
15
23
78
142
286
452
592