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How Astronomers Know — Evidence Lab

Scale of the Solar System

Estimated time
~18 min
Saved locally on this device
Learning goals
  • The solar system is mostly empty space. Distances between planets are enormous compared to the planets themselves.
  • MS-ESS1-3 — Students use proportional reasoning to describe relative sizes and distances.
Help & glossary
  • Use the hint ladder before checking your answer — hints get more specific.
  • Incorrect answers can be retried. Feedback explains why.
  • Constructed responses (CER) are self-checked — nothing is sent to a server.

Question 1 of 3

One astronomical unit (AU) is the average distance from Earth to the Sun. Neptune orbits about 30 AU from the Sun. If you built a scale model where 1 AU = 5 meters, how many meters away from the Sun should Neptune be?

Astronomers use the astronomical unit to keep distances manageable. Multiplying an AU distance by a chosen scale gives you a model distance.

meters

    Sources