Make a Solar System Scale Model

A model is a representation of something that is too large, too small, or too complex to display in other ways. We make models of a battleship on our desk because we could not fit a real battleship on our desk and the cost would be too great, this meets the criteria of being too large and too complex. We make a model of A cell because it is too small to see without a microscope, this meets the criteria of being too small. We make a model of a machine in many cases because it is too complex.

Our solar system can be modeled in the classroom. The graphic provided is not drawn to scale, but it should give you the idea. If you have a section of the classroom or hallway in your school and it is 39.5 inches wide you could put a mark on the wall at "0" and that is where you would dray an 11 inch diameter sun. Then 39 inches away from the sun you would draw Pluto. Pluto would only be 1/10 of an inch in diameter. The earth would be just 1 inch from the sun and would be 1/10 of an inch in diameter. If you have about 80 inches of wall space, you can simply double all the measurements. One problem is that if you try to draw a planet like Venus, it is only .04 of an inch on this scale. On this scale it is like the period at the end of a sentence. (This is why the graphic is not fully to scale.) NOTE: Even if you can not draw the model fully to perfect scale, if you can come close, you are giving students a better perspective. At least keep them drawn with a good relative scale as compared to each other. The distances from the sun are easier to model relatively correctly.) If I do this in the hall and have the room I might triple the distances. I might multiply the planet diameters by a factor of 10, so we have something we can actually see, but I will mark this change on the chart model.

When this model is drawn on the wall it gives students a much better perspective of just how large the sun really is when compared to the Earth and the teacher can explain that the reason it looks relatively small is because it is actually far from the Earth. In fact the Earth is one (Unit) from the sun in terms of our scale. Students get a better idea of just how far Pluto is from the sun and why it would be a cold and dark planet (if it were a planet).

Once a solar scale model is displayed it can become a springboard to talk much more about each planet, the orbits of the planets around the sun, the tilt of the Earth and why we want to explore outer space. Students can not fully appreciate the size of the Milky Way if they don't have a reasonable concept of the size of our solar system and when you then consider the size of the universe it becomes beyond belief.

Some hobby shops will sell kits which can model the solar system in the form of a mobile that a student could hang from the ceiling. They may have models of just the "moon" which gives students a chance to see the craters that have been discovered by professional astronomers (and backyard astronomers), and the names they have been given. You can have students do research about where we have landed and walked on the moon. Look up solar system models on the internet and find out more about the planets.