Chart 1: Bringing the Solar System Down to Earth
- Look at Chart 1 (below), which gives the diameter of the planets and the sun in kilometers.
- The sun is 1,380,000 km in diameter. You will assign the sun a diameter value of 1.
- To get the diameter value of Mercury, divide 1,380,000 km by 4989. The answer would be 277. Place this number in the part of the chart marked "# times smaller than the sun." Repeat this procedure for the other eight planets. For instance, Venus would be 1,380,000 km divided by 12,392 km. Record this value in Chart 1.
- For the last column in Chart 1, you will assign a scaled-down value for each of the planets. Begin with the sun and assign the sun a value of 1 meter (1000 mm). Calculate the value of the planets by dividing 1000 by the number of times smaller you calculated that planet to be than the sun. For instance, Mercury will be calculated by dividing 1000 by 277. The answer will be 3.6 mm. This will be entered in the chart. Do this for each of the planets.
- When the chart is complete, the last column will represent the diameter your group will use to represent each planet in the activity.
| Object | Diameter (km) |
# Times Smaller than Sun | Scaled-Down Diameter (mm) |
| Sun | 1,380,000 | ||
| Mercury | 4,989 | ||
| Venus | 12,392 | ||
| Earth | 12,757 | ||
| Mars | 6,759 | ||
| Jupiter | 142,749 | ||
| Saturn | 120,862 | ||
| Uranus | 51,499 | ||
| Neptune | 44,579 | ||
| Pluto | 2,414 |
Excerpted from Hands on Science Activities with Real-Life Applications by Pam Walker and Elaine Wood.
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