Making a scale model of the solar system is a good way to appreciate just how big space really is. In this document I'll show how big the planets would appear and how far apart they would be for a couple of different scales. For lots more info on the solar system, you might also want to look at Bill Arnett's wonderful Web site, The Nine Planets.
I've also added an entry to show how far away the nearest star, Alpha Centauri, would be placed.
When working with distances in the solar system, astronomers find it convenient to describe the distances in terms of the typical Earth-Sun distance (which is about 150 thousand kilometers). We call the Earth-Sun distance an astronomical unit or AU. Let's start by taking 1 AU to be modelled as being 1 meter.
Here are the diameters (given in millimeters) of the planets and their distances (in meters) from the Sun.
| scale | scale | |
|---|---|---|
| size | distance | |
| (mm) | (m) | |
| Sun | 9.3 | 0 |
| Mercury | 0.03 | 0.39 |
| Venus | 0.08 | 0.72 |
| Earth | 0.09 | 1 |
| Moon | 0.02 | |
| Mars | 0.05 | 1.52 |
| Jupiter | 1 | 5.2 |
| Saturn | 1 | 9.5 |
| Uranus | 0.3 | 20 |
| Neptune | 0.3 | 30 |
| Pluto | 0.02 | 39.4 |
| A Centauri | 268 144 |
Now let's suppose that we model the Earth as a sphere 1 cm in diameter, then the scale diameters (in centimeters) and distances (in meters) are:
| scale | scale | |
|---|---|---|
| size | distance | |
| (cm) | (m) | |
| Sun | 110 | 0 |
| Mercury | 0.4 | 46 |
| Venus | 1 | 84 |
| Earth | 1 | 118 |
| Moon | 0.3 | |
| Mars | 0.5 | 179 |
| Jupiter | 11.4 | 611 |
| Saturn | 9.6 | 1122 |
| Uranus | 4.1 | 2255 |
| Neptune | 4.0 | 3535 |
| Pluto | 0.2 | 4638 |
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