Our solar system, which sports a sun at the center with nine orbiting planets, is very large, but in the scale of the entire Milky Way Galaxy, we are very small and probably not visible from other galaxies.

The scale of the solar system can be scaled down to feet. When talking to schoolchildren, I have students volunteer to represent the sun and planets. A student stands in the room holding a golf ball suspended on a string to represent the sun. Other students standing nearby represent the planets.

If the 1.68-inch-diameter golf ball represents the sun’s diameter of 864 thousand miles, then the 93 million-mile distance from Earth to the sun would equal about 15 feet. The student representing the Earth would have to hold a BB-sized Earth and stand about 15 feet away. Actually the BB is far too large to represent Earth with this scale. Rather than speak millions of miles, solar system distances can be much easier to understand if we convert distance to “astronomical units” or AUs. The average distance from Earth to the sun is considered to be one AU.

The planet Mercury has an average distance of 0.387 AU from the sun; Venus = 0.722 AU; Earth = 1; Mars = 1.52 AU; Jupiter = 5.2 AU; Saturn = 9.58 AU; Uranus = 19.2 AU; Neptune = 30.1 AU and Pluto’s average distance from the sun is an astounding 39.5 AU.

If the student holding the BB-sized Earth is 15 feet from our golf ball-sized sun (1 AU), then how far must a student stand with a half grain of rice to represent Mercury? Solving a simple ratio problem, the distance is 5.8 feet. Since Venus is almost the size of Earth, let’s place a student holding another BB to represent Venus at 10.8 feet. Another student would hold a small peppercorn or something smaller than a BB representing Mars at 22.8 feet. The student representing Jupiter would hold a very small marble or ball bearing at a distance of 78 feet. Saturn would be almost 144 feet — we might be in the middle of the playground by now. Uranus is at 288 feet, or almost the length of a football field. Neptune would be 150 yards away. And finally, Pluto in our small scale of the solar system would be almost 200 yards from the golf ball and would be represented by a poppy seed. We could change the scale so that an AU represents an inch to fit a classroom, but the sun and planets would be so small that the students wouldn’t have room to stand next to each other.

If this is the scale of our little solar system living in the suburbs of our Milky Way, imagine the scale of the entire universe.