Barbara Chemelowski, age 10, of West Warwick, R.I., for. her question:

Do they know how stars are formed?

There are about 100 billion stars in our stupendous Milky Way galaxy. So astronomers have plenty of stars to study.

And one of their favorite topics is the life story of the stars. They tell us that the old timers burn up their fuel and finally their blazing furnaces die down. But, meantime, new stars are born in other parts of the galaxy.

Strewn among the teeming stars are vast clouds of dusty gases. As far as we know, this cloudy stuff is used to create new stars. We do not know all the details. But in some mysterious way, vast masses of cloudy material close in and begin to gel. Then in other mysterious ways the big ball begins to spin around. It gets hotter and hotter  hot enough to light up a nuclear furnace.

At this point, a blazing new star is born. And, of all things, astronomers suspect that most new stars also form families of planets  just as our sun did.