A Solar System number line
25 minutes · Long paper strip · Pencil · Ruler
Your investigation
- Draw a distance line using 1 centimeter for 1 astronomical unit (AU). Mark the Sun at zero.
- Mark these rounded average distances in AU: Mercury 0.4, Venus 0.7, Earth 1.0, Mars 1.5, Jupiter 5.2, Saturn 9.6, Uranus 19.2, Neptune 30.1.
- If your paper is too short, join strips or change every distance using the same scale.
- Use dots, not planet-sized circles, and label “average distances to scale; planet sizes not to scale.”
Think, draw, explain
Which region has wider average gaps, inner or outer planets?
At this scale, is Jupiter only one centimeter beyond Mars?
Grown-up guide & possible answers
- The outer-planet gaps are much larger. A uniformly spaced planet row does not represent distance accurately.
- No. Their average-distance difference is about 3.7 AU, or 3.7 centimeters in this model. Planets are not always lined up in space.