
9  pieces of paper
1  roll of toilet paper
1  ruler
1 set of planet
printouts (provided or 1 compass
to draw your own.)


1
 pair of scissors
1  calculator
1  long hallway
or outdoor space of at least 110 feet
(30.5 meters). You can make a partial
model if your space is smaller.
1  table with
measures of planet radius and distance
to the Sun relative to scale. 






You
can construct a scale model of the solar system to help visualize
the relative sizes of the Sun and planets, and the distances
between them.
In this activity, you'll investigate the concepts
of relative size and distance by creating a basic model of
our solar system.
The image shows Saturn's famous rings. Faint rings can be
found around Uranus, Jupiter, and Neptune.


1. 
Cut out the planet
printouts provided, or using the measurements in the
table above, use your compass to draw circles on paper.
Note that this activity uses two scales: one for the printouts
and cutouts, and one for the distances between the planets.
This is due to the enormous distances involved. The planet
cutouts would be too small to use in our scale model.
The second column in the table is for size, the last column
is for distances. 
2. 
If you choose to draw
your own circles, label each planet. Cut the circles out
and use them as your planets.

3. 
Choose a point at one
end of a hallway, large room, or outdoor space as the
Sun and mark it as your starting point.

4. 
Without looking at the
table, place each planet in order of the distance you
think it is from the Sun. As a reference, use 33.5 inches
(85 centimeters) for the distance between Earth and the
Sun.



5. 
Using the table, measure the
distances by rolling out the toilet paper. Mercury is
2.9 sheets relative to the Sun, Venus 5.5 sheets from
the Sun, etc. See how well your family did at estimating
the distances. Move the planets to their proper distances,
and you've built a scale model of the solar system. 

This activity helps demonstrate
the immense scale of our solar system. The sizes of
the planets vary greatly as do the distances between
planets and their distance from the Sun. The size of
the Sun in this scale (which wasn't included in this
activity) would have been 38 1/2 inches (97 centimeters)
in diameter (19 1/4 inches in radius).
Derived
from "A Toilet Paper Solar System Scale Model":
from Project Pulsar, St. Louis Science Center.
Learn more about the solar system at The
Nine Planets Web site.
Learn more about constructing scale models on the Exploratorium's
Build
a Solar System Web site.
Find more handson Astronomy Activities at the At
Home Astronomy Web site.




