Marlene Goldman,.age 12, of Somerset, New Jersey, for her question:

Are there really other solar systems?

For a long time, astronomers suspected that ours is not the only system in the universe. Then a few years ago, planets were detected in the neighborhood of several stars. Planets are small, dark bodies.and the only ones our .instruments can detect across, the vast distances between us and the stars would have to be as big or bigger than Jupiter.

Those found so far are whoppers . But they prove that other stars do have planets. And most likely the solar systems with whopping planets also have others too small to be detected.. Astronomers now suspect that there are millions and perhaps billions of other solar systems in our Galaxy. Our planets were formed when the starry sun was born. A recent theory suggests that this may be the usual procedure. If this is so, there may be about 100 billion solar systems in our Galaxy. Certainly we know that ours is not the only one.