Cynthia Shadwick, age 12, of Black Lick, Ohio, fur her question:
What is the Solar System?
The Solar System is a parent star with its family of children. It is shaped like a huge saucer with the star, which is our glorious sun, in the center. The children of the sun are of various kinds. The biggest are the nine planets. Some of the planets have moons, or satellites. Altogether, there are more than 30 satellites in the Solar System, not counting the man‑made ones.
Among the smaller Solar children arc the asteroids, or planetoids. There are thousands of them. The comets, too, are Solar children. There are scores of them, though we rarely see one, The smallest members of the Solar family are the meteors. They range in size from a grain of sand to a large buildings and there are countless numbers of them.
Like any good parent, Old Sot has strict rules for the safety of his family. These laws prevent the Solar children from bumping into each other, falling into the sun or wandering off into the cold, lonely oceans of outer space.
Everything in the Solar System is on the move, but everything must move in a certain way. The planets rotate or spin around like tops. They also revolve around the sun, each keeping to its own path or orbit. The satellites rotate and revolve around the planets, moving with them around the sun. The comets and asteroids revolve around the sun and the meteors speed through the empty spaces between the planets.
Even the sun rotates, showing us first one side and then the other of his radiant face. And the sun also revolves. It revolves around in a great cartwheel of stars we call the Milky Way, taking its family along with it. The Solar System, it seems, is forever dancing around the heavens.
The Solar System is about 8,000 million miles wide from side to side. This huge rim is the orbit of little Pluto, the planet farthest from the sun.
It is almost 40 times farther from the sun than we are. The orbits of the other planets are widely spaced, each one nearer the sun until we come to Mercury, which is 36 million miles from the sun.
The asteroids tumble around the sun roughly between the fourth and fifth planets, Mars and Jupiter. The orbits of the comets are long and very narrow. We see them only when they loop around the sun.
All the children of the sun are cold and. solid, giving off no light or heat of their own. Only the sun, a vast, blazing atomic furnace, gives forth light and heat. Compared with it, its children are very small, indeed. About 99 per cent of the mass, or weight, of the entire Solar System is in the sun.
The size of the Solar System is hard to imagine without a scaled‑down model. If the sun were the size of a beach ball, Pluto would be the size of a very small pea a mile and a half away. Jupiter, the biggest planet, would be the size of an orange and a quarter of a mile away. Earth would be the size of a large pea, about 215 feet from the beach ball sun.