A Scale Model of the Solar System

Summary

For this homework, we want you to describe an astronomical scale model.

Background

The distances and numbers we will discuss in this class are so large that they are often hard to relate to. One way of making these numbers more comprehensible is to shrink it down - to make a scale model. Architects and engineers will often make scale models to see what their project will look like before building it; model railroads and doll houses are other examples of scaled down versions of the real objects. The basic idea behind all of these is to ``scale'' the real thing down - make everything the same fraction of its real size.

Assignment

Design a scale model of the solar system and its nearest neighbor. Your model should include the following:

The Earth
The Sun
The Moon
Mars
Jupiter
Pluto
The nearest sun-like star, Alpha Centauri

All of the relevant numbers for the sizes and distances for these objects can be found in the appendices (1) of the text book. To convert them to your scale, simply divide them by your chosen scale factor. For example: If you choose to make a 1/10th scale model, you would then make the Earth (with a real radius of 6378 km) have a radius of 637.8 km in your model. Obviously, picking the correct scale is important. Making a 1/10th scale model of the Earth isn't very useful, but making a 1/1000th scale model of a doll house isn't going to be much good either. So choosing the right scale to display your information is important. If you are having trouble choosing a scale (or with any other part of this assignment) talk to your TA.

What to turn in:

Turn in a paragraph explaining how and why you chose the scale that you chose.
Turn in your data table, showing both how large and how far away the above objects would be in your model. Describe a common object that you could use to actually build this scale model; for example, if your scale model makes the sun about 12 inches in size, you might use a basketball.

(1) - The Appendices: The back of astronomy textbooks are full of data tables of useful information. For this project, the most useful parts are unit conversions, the information on the sun, and the information on the planets. The semi-major axis is the average distance from the planet to the sun. Alpha-Centauri is just like the sun in size.