James Mencel, age 8, of Bridgeport, Conn., for his question:
How many other solar systems are there?
The people of our earth have always wanted to visit other worlds in the heavens. Suddenly they found they could do it. This idea was the start of the space Age. Some grown ups still believe that earthlings cannot visit other solar systems but the young people of the space Age know better.
Your grandparents were once young children who admired the wonders of the starry heavens, just as you do. But there were not many experts around to answer their questions. The children of so years ago did not have much of a chance to learn about the sun and its planets, the moon and the stars. This was sad for they wanted to learn about space, just as you do.
All young people love the starry sky, and you are lucky to live in the space Age. But remember, the space Age still is very new. Even experts are just beginning to learn the facts and We can learn only what they can tell us. The space experts will learn many new facts and solve many mysteries and even change some of the ideas that they have now. Your grandchildren may say that your space ideas are old fashioned.
Our solar system is the starry sun and its family of nine planets. We know a lot about it because we are part of it. It is near enough to watch and study. But one thing about it is very hard to grasp especially for the youngest space agers. It is bigger than most people think. Mariner II took months of fast traveling to reach Venus. This spacecraft would take years to cross our saucer shaped solar system from rim to rim.
Outer space is enormous and immense and there space trips would be very long. A fast jet would need a thousand years or more to reach the nearest star to our sun ¬ and outer space is strewn with billions of stars. No one could count them, but experts guess that our universe has about l00 billion stars.
The experts know for sure that one star has a big planet. They have some facts that seem to show that three or four other stars may have planets. So we know that our solar system is not the only one. Our experts think that many other stars have planets, but so far they cannot prove it. They say that there may be more than a hundred thousand solar systems in our universe. No one is sure of this and no one can imagine how many solar systems there may be in other universes. But We are pretty surf that space agers of the future will find them.
Our island universe is the star studded galaxy that spins like a giant pinwheel in the heavens, and our solar system is a tiny part of it. Its other solar systems may have planets, maybe a few will be like our own wondrous world. When spacemen of the future reach them, they may only find living plants and animals. And they just might find intelligent people on other worlds.