Curtis L. McLarty. age 14, of Wichita, Kansas, for his question:
Is outer space a complete vacuum?
This is what everybody thought until the 1950s. When the first satellites were sent aloft to orbit the earth, everybody expected to find that the space beyond our atmosphere is an empty vacuum. Then came one of the first of many space age surprises. True, there is not much material Out there between the planets, but there is some. And what's more, all of it is charged with dynamic energies.
Space age exploration has revealed that the vast reaches of space between the planets if filled with amazing material called plasma. So far we have not explored beyond the Solar System. But astrophysicists suspect that similar material also fills the oceans of outer space between the stars.
On earth, we are used to the three states of matter that come in solids, liquids and gases. Plasma has been defined as a fourth state of matter. It is somewhat like the thin gaseous material we use inside a fluorescent light bulb. The glass tube is an almost vacuum containing a very skimpy mixture of gaseous particles. When energized with an electric current, they glow with light.
The far flung stars in outer space are seething nuclear powerhouses, emitting light, radio and other dynamic electromagnetic energies. These energies stream out from star to star, crossing the vast oceans of outer space. In addition, the stars and planets, the moons and every speck of matter in the universe also exert the forces of gravity in all directions.
All these teeming, streaming energies extend throughout our entire Galaxy. In the spaceous oceans between the stars and planets, they en¬counter thinly scattered particles of matter. Some of this material was emitted by stars, novas and other dramatic nuclear upheavals in the Galaxy.
For example, our sun is but a medium star, yet it constantly emits a so called solar wind of charged particles. Solar flares and sunspot activities emit streams of particles that cause auroras in our skies and disrupt radio communications in our upper atmosphere.
The hundred billion stars of our Galaxy have been emitting particles of matter for billions of years. This may account for much and perhaps most of the gaseous plasma material that occupies outer space. And most likely the energies that charge the gaseous plasma also are emitted by the stars.
A vacuum, of course, is completely devoid of any particles of matter whatever. We now know that the space between the earth, the moon and our neighboring planets is not a complete vacuum. However, the material in the plasma which fills it is not very substantial. If the earth were hol¬low and filled with average space plasma, ix would hardly contain enough solid material to shape an orange.