The solar system consists of the Sun, nine planets, some 60 or so moons, and assorted minor materials (asteroids, meteoroids, comets, dust, and gas). All of these objects are tiny in comparison to the distances that separate them. Imagine the solar system scaled down such that distances to the planets could be spaced along a 10-kilometer hiking trail. On such a scale the Sun would be represented by a ball only 2.3 meters in diameter. The distribution along the trail and the model sizes for each of the planets are shown in the following table:
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TABLE 1
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Scale Model of the Solar System
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Object
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Position along the Trail
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Diameter of Model Sphere
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Comment
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Sun
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At start of trail
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2.3 meters
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7.6 feet
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Mercury
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100 meters
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0.8 cm
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Small marble
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Venus
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180 meters
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2.0 cm
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Large marble
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Earth
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250 meters
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2.2 cm
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Large marble
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Mars
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390 meters
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1.1 cm
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Small marble
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Jupiter
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1.3 kilometers
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24 cm
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Small (youth) soccer ball
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Saturn
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2.4 kilometers
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20 cm without rings
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Small (youth) soccer ball
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Uranus
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4.9 kilometers
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8.6 cm
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Baseball
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Neptune
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7.6 kilometers
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8.3 cm
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Baseball
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Pluto trail's end
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10 kilometers,
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0.2 cm
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BB, or small ball bearing
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Comets
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To 25,000 kilometers
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20 μ – 200μ
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Dust particles
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A Brief History of Astronomy
The Solar System
