A scale model compresses measurements by a common factor. Using one factor for diameters and distances shows why diagrams often enlarge planets. Average orbital distances are comparisons, not current positions or fixed gaps between neighbouring planets.
Space · Discover & try
How big is our Solar System?
Reading level 5 of 5 · AdvancedChange
Word help
Scale
A consistent relationship between model measurements and real measurements.
Astronomical unit
A length of about 150 million kilometres, close to the average Earth–Sun distance.
Diameter
The distance across an object through its centre.
Watch · Try · Explain
See how it works
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Average orbital distances and planet diameters, shown on separately labelled scales. This is not a live positions map.
What to look for
- Compare the inner-planet gaps with the outer-planet gaps.
- Switch between the size and distance views.
- Read whether planet symbols share the distance scale.
Explain what you noticed
Why are planets often enlarged in a Solar System distance diagram?
Keep this idea: Planet size and distance are different measurements and need explicit scales.
Follow the sources
- NASA — How Big Is the Solar System?
- NASA Jet Propulsion Laboratory — Make a Scale Solar System
- NASA Jet Propulsion Laboratory — Solar System Sizes and Distances: Reference Guide
Source material checked 2026-10-28. Explanations and activities by Nepedia. Agency source links do not imply endorsement.
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