Toilet Paper Solar System


     It's hard to image the vast distances in the universe. We can image twelve inches or ten feet, but 93 million miles is a bit hard to comprehend. Here's an interesting way to get an idea of the distances between the planets and Sun.

What You Will Need

  • Roll of toilet paper or you may use a blank cash register tape from an office supply store but it must be at least 125 feet long.
  • Different colour magic markers or felt tip pens.
  • A tape measure
  • A long hallway or very large room
  • Optional: You might like to use pictures of the planets if you can get some small enough to fit on your toilet paper or tape. This will add some colour to your model.

Before you Start

      There are nine planets in our solar system. They are, from the Sun outwards, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. There is also an asteroid belt in between the orbits of Mars and Jupiter. The asteroid belt is made up of leftover chunks of rock and ice from when the planets formed. There are also other chunks of icy rock, some of which are comets. Comets orbit the Sun like the planets but their orbits are much more elliptical and then often go to the farthest edges of our Solar System.

      In this activity we will be using the average distances between the planets and Sun. The orbits of the planets are not perfect circles, but rather, ellipses which are sort of like a squashed circle. An elliptical orbit means that sometimes the planet is closer to the Sun than at other places in it's orbit. For example, when the Earth is at it's closest point to the Sun (perihelion) it is 91.3 million miles. When the Earth is at it's most distant point from the Sun (aphelion) it is 94.5 million miles. To simplify things, we'll use an average distance between aphelion and perihelion.

      One of the ways astronomers measure distances is by astronomical units (AU.) One AU is equal to 93 million miles, the average distance from the Earth to the Sun. For our model, we will allow one AU to equal three feet (1 yard.) You may also use a smaller proportion such as one AU equals 1 inch, which will make a much smaller model.

Activity

      We will use the table below to construct out toilet paper solar system. This first column in the table lists all of the objects we will use in our solar system. The second column in the table lists the distance from that object to the Sun in miles and kilometers. The third column lists the distance from the object to the Sun in Astronomical Units. The next column shows how far the object will be from the Sun on our toilet paper scale. The last column shows the distances from one object to another in our toilet paper solar system.

      As an example, take a look at Mars. The average distance from Mars to the Sun iin the real solar system is 142 million miles, or 228 million kilometers. The same distance in astronomical units is 1.52. On our toilet paper solar system, Mars will be 55 inches from the Sun, and 3.7 feet from the Asteroid Belt.

      To make your solar system, unroll some toilet paper or register tape and draw a Sun at the end of it. Now use the "distance between objects" column to plot the members of the solar system. Draw Mercury 14 inches from the Sun. Venus will be 12 inches from Mercury and Earth will be 10 inches from Venus. Continue unrolling paper as needed to plot the locations of the rest of the objects on the chart. You won't be able to plot past Pluto because of the enormous distance to the next object!

      See the illustration below to see an example of how your solar system should look. It's fun to keep your solar system to show others and you can add to it by learning some facts about each of the objects. Although you can't actually show how var away the Oort cloud and Proxima Centauri is, you can tell folks. You might also add that if our space shuttle tried to reach Proxima Centauri, it would take 125,000 years!



This is a list of planetary distances from the Sun to the planets and from each other. Three feet equal one Astronomical Unit.
Object Average Distance
from Sun (Miles/Km)
Average Distance
from Sun (AU)
Distance from Sun
on toilet paper
Distance between objects
Sun - - - 14 inches
Mercury 36 million miles
(58 million km)
0.38 14 inches 12 inches
Venus 67 million miles
(108 million km)
0.72 26 inches 10 inches
Earth 93 million mi.
(150 million km)
1.00 36 inches 0.1 inch
Moon 93 million mi
(150 million km)
1.00 36 inches 19 inches
Mars 142 million mi.
(228 million km.)
1.52 55 inches 3.7 feet
Asteroid Belt 256 million mi.
(411 million km.)
2.75 8.25 feet 7.4 feet
Jupiter 483 million mi.
(778 million km.)
5.20 15.6 feet 13 feet
Saturn 885 million mi.
(1,426 million km.)
9.59 28.6 feet 29 feet
Uranus 1,787 million mi.
(2,877 milion km.)
19.2 57.6 feet 33 feet
Neptune 2,800 million mi.
(4.508 million km.)
30.1 90.3 feet 29 feet
Pluto 3,699 million mi.
(5,955 million km.)
39.5 119 feet 71.6 miles
Oort Comet Cloud 11,700 billion mi.
(18,837 billion km.)
126,00 71.6 miles 80.5 miles
Alpha Centauri
(nearest star to Sun)
24,863 billion mi.
(40,029 billion km.)
268,000 152 miles 80.5 miles

Copyright © 2001 Kathy A. Miles and Charles F. Peters II