Take a second to consider the vast distance between the Earth and the Moon. The radius of the Earth is about 6.4 million meters (6,400 km or 3,970 mi). The distance to the Moon is 384 million meters (384,000 km or 238,000 mi)! That distance is 60 times the radius of the Earth! Take a look at the picture below to get some idea of the vastness of this distance, which on a cosmic scale is really quite small:

The relative sizes and separation of the Earth–Moon system are shown to scale above. The beam of light is depicted travelling between the Earth and the Moon in the same time it actually takes light to scale the real distance between them: 1.255 seconds at its mean orbital distance. The light beam helps provide the sense of scale of the Earth-Moon system relative to the Sun, which is 8.28 light-minutes away (photosphere to Earth surface). This image is from Wikipedia’s Moon page.

Feel insignificant yet? Well, if not then doing this activity might help. You will create a scale model of the solar system by drawing the size of the planets on paper and pacing out the distance between them, taking the radius of the Sun to be 1.0 m. The data you will need are found below:

1. Take the radius of the Sun to be 1.0 m (100 cm) in your scaled-down Solar System. What is the conversion factor you will use to convert the radii and orbital distances in the table above? You must divide the scaled radius of the Sun by the actual radius of the Sun.
2. Multiply all values in the table at left by the scale factor to calculate the scaled-down sizes of the orbits and planets. Fill them in the blank chart above.
3. Using a blank piece of copy paper, draw circles representing the various planets. Draw them to the correct scale using a compass and ruler and label them clearly. You may need more than one sheet of paper in order to draw all of the planets. Feel free to use color and your knowledge of the appearance of each planet to add a creative touch to your work.
4. How much bigger is the radius of the Earth’s orbit (its orbital distance) than the radius of the Earth? Divide the orbital distance by the radius of the Earth. Based on this calculation consider the following: Imagine that you are out in space high above the north pole of the Sun. In fact, you are so far up above the Solar System that you can see the entire orbit of the Earth in one glance. Given the size of the Earth compared to the size of its orbit, do you think you could find the Earth in all that empty space? Why or why not?
5. The nearest star to the Sun is Alpha Centauri (also written as α Centauri). It is about 4 light-years away (3.78 × 10¹⁶ m). One light-year is the distance traveled by light (at 3 × 10⁸ m/s) in one year or 9.46 × 10¹⁵ m. Compare the radius of Pluto’s orbit to the distance to α Centauri. How much farther away is α Centauri compared to Pluto’s orbital distance? That is, how many times farther away is the nearest star than the outer edge of the Solar System? What does this tell you about the amount of space between stars in our galaxy?
6. Calculate the orbital distances in feet (meters × 3.28 ft/m) and miles (ft ÷ 5280 ft/mi). Put the results in the table below. Use the map provided with this assignment to mark the locations of the planets’ orbits. Set the Sun at the location of Scarborough High School and place the planets on the map using the map’s scale. Only the Outer Solar System (Jupiter through Pluto) will actually be on the map. The Inner Solar System (Mercury through Mars), being so much smaller, will have to be placed in its own box. Use the scale given in the box to place the Inner Solar System planets around the Sun.

7. Split up into groups of 3 or 4 students. Take your charts down to the hallway by the study center and art rooms and choose a floor tile to represent the position of the Sun. Pace out the scale distances to the various orbital distances by counting floor tiles, which are all about 1 ft on a side. Also, a good guess for the size of your step is about 3 ft. A better guess can be made by pacing 10 normal steps and measuring the distance you walked. Walk down the G hallway in the direction toward the main entrance of the school. Take one meter stick with your group since you will undoubtedly end up outside. Write down the locations within the school where you stopped for each planet:
   
   Mercury ____________________
   Venus    ____________________
   Earth     ____________________                            Moon ____________________
   Mars      ____________________
   Jupiter   ____________________