The Scale of the Solar System

Students build a mental scale model of the solar system, with a 2 foot Sun, to compare the true sizes of the planets with the far larger distances between them.

Grades 5-8About 15 minutes of narrated flight, plus discussion stops8 stops

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What students will see and do

Students fly from the Sun to Earth, the Moon, Mars, Jupiter, Saturn and Neptune, and finally rise above the whole solar system, while the narrator places each world in a model with a 2 foot Sun and gives travel times for light, cars, jets and spacecraft. The class pauses at three discussion stops: the Moon, Jupiter and the solar system overview.

Learning objectives

• Use a single scale factor to convert real planet sizes and distances into model sizes and distances.
• Compare the sizes of the Sun, Earth, Moon and planets using ratios such as 109 Earths across the Sun.
• Explain why the distances between planets dwarf the planets' sizes and why true scale drawings rarely fit on a page.
• Calculate travel times across the solar system at different speeds, including the speed of light.

NGSS connections

Stops on this journey

1. Shrinking the Sun
2. A Peppercorn World
3. The Moon Is Closer Than You Think (discussion stop)
4. A Moving Target
5. The Giant Jump (discussion stop)
6. Rings in the Distance
7. The Last Planet
8. Mostly Empty (discussion stop)

Vocabulary

• scale model
• scale factor
• astronomical unit
• light-year
• diameter
• orbit
• gravity assist
• ratio