Mark R. Malamatos, age 9, of Gary, Ind., for his question:

What exactly is the Milky Way made of?

It looks like a ragged arch of blurred white light, looping over the sky. No one had any idea of what it really was until about 350 years ago. Then a great man looked at it through a telescope that made faraway things look nearer. He saw that the Milky Way was made of millions of crowded stars. They were so close together and so far away from us that their light blends together in a blurred white haze.

Later we found out that there are vast clouds of dusty gases in the Milky Way. some are dark patches that hide the crowded stars behind them. some are bright with light shining from other stars. There are perhaps l00 million stars in the Milky Way and most of them are like our sun. There also are enormous clouds of bright gases and dark gases.