Our Solar System to Scale

Most of the representations of the Solar System are not to scale. They show the planets close together and even then they are not depicted with consistent scale. One image will show Jupiter being 3 earth diameters in size, another showing Jupiter 6 earths in diameter, when in reality Jupiter is over 11 earths in diameter. The distances between the planets are represented even farther from reality as any representation of the planets to scale that could fit on a page would not allow us to even see the planets.

There really wasn’t a great scale model of the Solar System, so I made a book. A book that took household items and created a Solar System model to scale. A hula hoop represented the sun. The earth a green pea. Jupiter was a softball and Saturn a tennis ball. All of these items were pretty close to scale (1.6 billion to 1 scale). The book also tries to tackle the distance between the planets by providing a scale model of the spacing of the planets. This is done by attaching a spool of string to the back of the book with a 1-1/2 inch diameter sun and the planets marked at their correct locations along the string. This is 36 billion to 1 scale model -- which puts Neptune out at 404 feet. It really puts things in perspective. I was surprised at how it helped to understand the true nature of the Solar System.

See a great example of the Solar System to scale, see this film by Wylie Overstreet and Alex Gorosh:

To Scale: The Solar System

Step 1: Write a Book...

The book consists of some explanation of the problem of scale and proposes the household item model. I found the Exploratorium's Solar system page very helpful in calculating out the respective sizes of the items. Since I used a hula hoop (34") as the sun, I called my model to 'Hula Hoop Scale'. The remainder of the book has information about the planets and along with each entry is a notation on how far away the planet would be in 'Hula Hoop Scale'. The final entry of the book talks about the Voyager spacecraft and what a great amount of knowledge they provided about the planets. Most all info is available on the internet in public domain.

I wanted my book to be hardcover so I could mount the string spool to the back.

There many online book publishers that will allow you to upload your book file and they will print a copy for you at a fairly reasonable price.

Step 2: Materials

To create this unusual book you will need:

1. The hardcover book (8-1/2" square size)

2. 8" Lazy Susan

3. An empty plastic spool (3D printer filament)

4. String (>405 feet in length)

5. 8.75" x 8.75" 1/8" thick hardboard

6. 1-1/2" dia. magnet

7. 1-1/2" dia. steel washer

8. Fast set epoxy glue

Step 3: Glue the Hard Board to the Back of the Book

Use fast set epoxy to glue the hardboard to the back of the book. It should fit without overlapping.

Step 4: Cut Down the Lazy Susan

Trim the lazy susan down so that it is smaller in diameter than the filament spool

Step 5: Glue the Lazy Susan Onto the Spool

Test fit the lazy susan to the spool and use the fast set epoxy to glue it in place. I put some masking tape under to edges in case some glue went over the edge.

Step 6: Glue the Spool Assembly to the Hardboard on the Book

Glue the spool assembly using epoxy to the back of the book.

Step 7: Attach the Sun to the String

Attach the 1-1/2" diameter magnet to the string and dress it up with an image of the sun.

Step 8: Glue the Washer in Place

Glue the steel washer onto the spool as a parking place for the sun magnet.

Step 9: Add Planet Labels to the String

Print out planet labels with name and approximate size if visible. I included the scale distance to the planet on the tag.

Step 10: To Use - Hold the Book Horizontally

Hold the book with the spool on top with the book horizontally to pay out string and you can insert your fingers into one of the smooth openings on the spool to reel it back in.