Astronomy 10, Spring 2000 The Scale of the Solar System
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The Scale of the Solar System

Let’s make everything one-billionth (10^-9) as big as it really is (9 orders of magnitude smaller)

The Earth: Diameter = 13000 km = 1.3x10⁷ m

1.3x10⁷x10^-9 ~ 10^-2 = 1.3 cm (a marble)

The Sun: Diameter = 1,400,000 km = 1.4x10⁹ m

(about 100 times the Earth’s)

so it must be 1.4 m (about a foot less than my height)

Earth-Sun Distance = 1.5x10¹¹ m (1 Astronomical Unit)

1.5x10¹¹x10^-9 = 1.5x10² m = 150 m

or about one-and-a-half football fields

Jupiter Distance = 5 AU,

Saturn Distance = 10 AU (downtown Berkeley)

Pluto Distance = 35 AU (6 km: Oakland)

1 Light Year: 3x10⁸ m/s x 3x10⁷ s/yr ~ 10¹⁶ m or 10¹³ km

scaled down, that would be 10^13-9 km or 10,000 km

(about the distance to Europe)

The nearest star is 4 light years away....

The center of our Galaxy is 25000 ly away!!

(scaled down, we’d be back out beyond the Sun...)