John Goguen, age 8, of Huntsville, Alabama, for his question:

What is outer space made of?

When your parents were eight years old, almost everybody thought that the spaces between the stars were quite empty. Then we sent man made satellites above the earth's airy atmosphere. Most experts did not expect to find anything up there. But what a surprise! In a few years we found out that space is not empty at all. And scientists keep finding more and more different things in outer space.

If you took a space ship to the stars, you might think that outer space is made of nothing at all. It has no breathable air    and the stars are many millions of miles apart. But so far as we know, the whole vast universe is filled with strange stuff called plasma. Its tiny particles of matter are thinly scattered and far apart. But there are other things besides fragments of matter. It seems that outer space is filled with invisible, mighty energies. Its plasma is a very frisky mixture of energy and tiny particles.

The stars pour out light, radio and other forms of electromagnetic energy. The force of gravity reaches out from stars, solid planets and from every speck of matter. These energies push and pull the plasma particles around. Sometimes they form long streamers, charged with electricity and magnetism. Sometimes they pinch bunches of these streamers together.

It seems that most of the fine fragments in outer space are particles like those used to build our atoms. They are so small and far apart that they amount to almost nothing. But not quite. If our moon were a hollow shell, it could hold enough plasma to weigh about an ounce or two. Many of the tiny particles are electrons and protons, charged with negative and positive electricity. All of them are pulled and pushed around by the mighty forces that fill the universe.

Here and there, a few particles in the plasma are whole atoms. Scientists keep finding different atoms out there in space. Lately they also found a few atoms packaged together in molecules. These seem to be near seething stars and vast clouds of dusty gases. The plasma in outer space is not all the same. In the vast vacant spaces it tends to be thin and weak. But it gets more crowded around a star. Actually, a blazing star is made of masses of peppy plasma, squeezed together in a tight ball. The same stuff used to make the stars is thinned down and spread out to fill outer space.

Nobody knows where it first came from. But we do know that the plasma in outer space goes through many changes. Sometimes its energies use its particles to build stars. Then the stars catch on fire and start strewing their plasma around in all directions. The thin samples found between the earth and the moon come from the seething sun, mixed with a little plasma that came from faraway stars.