We think of our planet Earth, our home, our only world, as if it were the center of the universe. For us, of course, our planet is huge. It takes a day to travel by jet plane between continents.

When we see drawings, artist’s conceptions of our solar system, we usually see a huge sun, surrounded by more or less small planets.

If our son was the size of a basketball, about 9.5 inches in diameter, the planet closest to the sun, Mercury, would be about the size of 1/30th of an inch, kind of like a poppy-seed. It would be 33 feet away from the basketball that is the sun.

Venus would be 1/12th of an inch in diameter, the size of a very small pebble, about 62 feet away. That’s it. There is a ball in the middle,  and these two grains of sand or pebbles circle at 33 feet and 62 feet away from the basketball.

Earth would be just a smidgen bigger than Venus, another tiny pebble, at a distance of 86 feet. Our moon would be a mote of dust circling our pebble at a distance of about 2.5 inches. A college basketball court is 84 feet long. So if the sun, the basketball, is under one net, the earth, grain of pebble 1/10th of an inch in diameter, would float at the other end of the court.

Let’s speed this up now.

Mars would be a grain of sand at 130 feet.

Jupiter would be a one inch marble at 445 feet.

Saturn would be a 3/4 inch marble at 820 feet.

Uranus would be a 1/3 inch, about the size of a pea, at 1,645 feet.

Neptune would be another pea, at 2,580. That’s almost half a mile.

These are all the planets. they would circle pretty much in a plane. Up and down in the imaginary sphere of the solar system there is nothing but dust, occasional comets coming in and leaving again. In addition, the planets don’t all just line up in one direction away from the sun, as I just described. They are in very different positions all around the son, so Uranus can be on one side, and Neptune on the other side of the sun and the two will then be almost a mile apart from each other.

The next star system, Alpha Centauri, which is 4.3 light years away, would be about 4,400 miles away. So if the sun were a basketball in New York City, the next star would be another basketball in Moscow.

Once I realize how little “stuff” there is in our solar system, and how far away the next one is, it gives me a feeling of awe of the size of our universe.

I wonder what I’d think about humanity if I were an alien traveler just coming around Neptune half a mile away from the sun, thinking about that little blue speck of 1/10 of an inch circling 86 feet from the sun – as all that humanity has got.

Our Earth is the only planet around for a very, very long distance.

We have to make it here.