How big is space, really?

Recently someone asked me, "How big is space?" Well, my answer was, "How big can you imagine?" When dealing with the great distances involved between astronomical objects, our mind sort of goes into a "boggle" state when we hear the numbers involved and we have a difficult time comprehending all of it.

Because the distance is often in the zillions of miles, astronomers have resorted to using a measuring device called a light year or the distance light (traveling at 186,000 miles per second) travels in a year. The figure comes out at about 6 trillion miles. That is a six with 12 zeros behind it. See what I mean about the "boggle" mentality?

The distance to the closest star to our sun is about four and a half light years and the distance to the nearest galaxy (the Andromeda Galaxy) is 2.5 million light years (here you can do the math).

And I don't even want to talk about the objects that are hundreds or even thousands of light years away. My calculator doesn't go that far.

Let us keep it simple, how about if we wanted to make a model of our own solar system, the sun and its family of planets." How do the distances there add up?

If we blow up a balloon or even take an ordinary bowling ball (both are about eight inches in diameter) and use it as our sun we would have to take 10 paces (if each pace is about three feet, one yard) before we get to the first planet, Mercury.

Here we could place the head of an ordinary pin glued or taped to a card to represent the size and distance to the planet.

Second we take nine more paces and place a peppercorn glued to a card for the scale and size of the second planet Venus. Take another peppercorn and walk seven more paces and place Earth.

Next take another pinhead 14 paces and label it Mars, and now get your hiking shoes on because you will have to walk 95 more paces before you place a chestnut or pecan for Jupiter.

Now we are about 135 paces or 45 yards from our sun. Are you beginning to grasp the distances and size scale involved here?

Keep your hiking shoes on because it really begins to get far here. From our Jupiter take another 112 paces and place an acorn or hazelnut to represent Saturn, the ringed planet. Keep going for another 249 paces and put a peanut or coffee bean for distant Uranus, 281 more paces and another peanut or coffee bean for Neptune.

Okay, one last jaunt, 242 more steps and put another pinhead for Pluto. Yes, I still consider Pluto a planet no matter what anyone else says. It was that way for many years and should stay that way. In fact, there have been objects found just as large as Pluto beyond its orbit but they have not, and probably will not, be designated as planets. They are called "Trans-Neptunian Objects" or the new word "Plutoids."

If you carefully measure how far we have traveled you will find it to be at about a half-mile (if your pace is as big as mine) to the end of the planets.

If you want to continue to the absolute edge of our solar system, out beyond the Kuiper Belt and the Ort cloud, put a marker another 2,000 yards away.

Now are you getting an idea of what kind of scale we are talking about for distance and that is just for our own solar system.

I haven't even started on the distance to the nearest star, Proxima Centauri (4.5 light years). If you really want to know, you need to put another bowling ball 4,000 miles away to keep the same scale. Sorry, I have to rest my boggled mind here.

SKY WATCH:

First quarter moon last Friday. Use the moon to find the planet Uranus on Saturday. Use binoculars. The tiny blue dot of the planet will be to the left of the dark, edge of the moon.

NEXT TIME:

More astronomical blathering