Calculations

• Math skills play an important part in building a model of the solar system because students need to figure out planets' distance from the sun and their diameters in order to build a scaled model of the solar system. Start by calculating the planets' size compared to the sun. Divide the sun's diameter by those of the different planets. You can use charts found at the website called "Bringing the Solar System Down to Earth" for diameter and distance calculations. Once you have gotten the diameters, calculate scaled-down diameters, which will be in millimeters. Start by assigning the number of one meter to the sun. Next use the numbers that you calculated for the planets' size compared to the sun, dividing them by 1,000.
  
  Next figure out the distance of the planets to the sun using astronomical units (AU), putting them on a separate chart. You will convert the distance of the planets from the sun, in millions of miles, to AU. Do this by dividing the planets' distance from the sun by the number 93 million. After doing this, create a scaled-down model of distance in millimeters from the AU figure that you get. First assign the value of 1,000 millimeters, or one meter, to the sun. Then take the numbers that you got from the first distance calculations and multiply them by 100.
  
  

Basic Model

• When you are creating a model at home to learn more about the planets, use a meter stick to measure the size of the planets and sun and the distance of the planets from the sun. Take your charts with you as a reference guide. You can do it outside and use materials such as straw, rocks or twigs. Use these materials to create an outline of the planets and the sun, using the diameter calculations as a guide. When you are creating the model, make sure that the sun is at one end, and the planets are placed in order, based on their distances from the sun. Use the scaled-down calculations of distances, following them when you are deciding where to place the planets.
  
  

Advanced Model

• If you are trying to build a more advanced model of the solar system, for your class or a science fair, use materials such an eight-inch Styrofoam ball for the sun and smaller balls for other planets. The largest ball should be used for the sun. The size of the other balls should be somewhat proportional to the diameters of the planets, which means that, after the sun, the largest ball should be for Jupiter and the smallest, Pluto. Use 10 wooden dowels, a box large enough to hold all of the "planets," black thread, pins, paint, construction paper and a large cork. You need black paint for the dowels and box; yellow for the sun, and other colors for the planets. Use construction paper that is red, white or yellow for the rings around the planets.
  Start by taping the box up on three sides and leaving one open, taking off the flaps on this side. Use black construction paper or paint for the box, so it is representative of the darkness of space. You may also want to dot white or yellow stars in the background. Next paint the balls that are you using to represent the planets and the sun.
  Next paint the dowels black and place one of them through the center of the cork. Make sure that there is about two inches at the top of the dowel, so that it sticks through the end of the box. Use the calculations you made to cut the dowels to the scaled-down distances. Insert nine dowels, one for each planet, into the cork in a pinwheel shape. Next tie one end of a thread to the end of each dowel and then tie the other end of the thread to a pin, which you will stick into each "planet." For the last step, put construction-paper rings around Jupiter, Saturn, Uranus and Neptune, using the most colorful and wide rings for Saturn. Once you are finished, you can spin the solar system model by twisting the end of the dowel not connected to a planet that is outside the box.