Silsan Ramsey age 11, of Tucson, Arizona, for her  question:

How many stars are there in the skv?

On a clear night, when the sky is full of stars, you might suppose that there are a million of them' or even perhaps ten billion, Actually, over a dusty city, we can never see more than a thousand stars and this number only very very rarely. Out in the country an a clear night we can see about two thousand stars. The best possible place to count the stars is in the clean clear desert air above the deserts of Arizona. There the starts look biggest and brightest and you might see perhaps 2,500 of them.

The stars in our sky all belong to the vast Milky Way system. Most of the stars in the system are too far away to be seen without the help of a telescope. It is estimated that the number of stars in our Milky way is about ten billion.