Scale of the Solar System
Use scale models, diagrams, or calculations to represent the relative sizes and distances of objects in the solar system, understanding that the distances between planets are enormously larger than the planets themselves
What a learner can do afterwards
- Explain that if the Sun were the size of a beach ball, Earth would be a pea about 26 metres away
- State that the distances between planets are much greater than the sizes of the planets themselves
- Create or interpret a scale model showing both relative sizes and distances
The lesson
You know space is huge, and you know the eight planets circle the Sun. But if you tried to draw the whole solar system on one page with the planets at the right size, the distances between them would not fit at all. A scale model fixes this: it shrinks every size and every distance by the same amount, so the true proportions still show up.
Picture the Sun shrunk down to a beach ball, about 30 centimetres across. On that same scale, Earth shrinks to a pea, just a few millimetres wide. Now for the surprising part: that pea sits about 26 metres from the beach ball, roughly as long as two school buses parked end to end.
A scale model only works if you shrink sizes and distances by the exact same amount. If you shrank the sizes enough to fit the planets on your desk, the distances would need to stretch across a football field, and the planets themselves would shrink to invisible specks of dust.
One scale for both size and distance shows that planets are tiny points scattered across huge stretches of empty space.
Watch it
Where it sits
Learn first
This opens up
Nothing builds on it yet.
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.