Download The Solar System Purpose

Physics PHYS 102
General Astronomy
The Solar System
Purpose
In this lab we will construct a scale model of the solar system. It turns out the solar system is much bigger (and
emptier!) than most people imagine.
Procedure
Our goal is to create an approximately scale model of the solar system on the Houghton College campus. To do
this, we first need to determine the scaling factor. Examine the photograph of Houghton College in Figure 1.
We need to put a scale on the photograph in order to know where each planet should go.
1. To do this, go outside with the measuring tape, and measure the length of the Science Building. The length
of the Science Building (in meters) is: _________.
2. Now, using the map in Figure 1, determine the scaling factor between the map and the actual campus. This
will be the length of the building on the map divided by the actual length. The scaling factor is:
________________.
3. Now draw a line on Figure 1 where you intend to lay out your solar system model. We will need to limit
the size of our scale model of the Solar system to this dimension. The length of the solar system model will
be (in meters): _________.
4. Now figure out the scaling factor between the solar system and the campus. This will be the length of your
solar system model divided by the average distance from the Sun to Pluto (5.91012 m). The scaling factor
is: ________________.
5. Using this scaling factor, complete Table 1.
6. Make a clay model of each planet with the appropriate scaled diameter. Some of these planets are going to
be very tiny – just try to get the right order of magnitude (i.e. don’t worry even about a factor of two…).
You may want to tape the smaller planets to a card. Draw an appropriately-sized circle on a sheet of paper
for the Sun.
7. Mark on your map of Houghton College (Figure 1) about where each planet should go.
8. Go outside and make your scaled-down solar system.
Answer the following questions:
1. Do the planets make up a very large part of the total volume of the Solar system?
2. An average person might drive a total of 12,000 miles in one year. How does that compare to these solar
system distances?
3. The nearest star is Proxima Centauri, which is about 4 light years from Earth. This is about 7000 times the
Sun-Pluto distance. Where would Proxima Centauri be in your scaled-down model?
Table 1. Distances from the Sun and diameters of objects in the Solar system.
Object
Sun
Diameter
(km)
Distance
from Sun
(106 km)
Scaled
Distance
from Sun (m)
Scaled
diameter (cm)
1,400,000
Mercury
4,900
58
Venus
12,100
108
Earth
12,800
150
Mars
6,800
228
Jupiter
143,000
780
Saturn
120,000
1,430
Uranus
51,200
2,870
Neptune
48,600
4,500
Pluto
2,200
5,900
2
Figure 1 -- Houghton College Campus
3