Kelly Brenzikofer, age 11, of Florence, Kansas, for her question:

What happens to the stars in the daytime?

The stars, as we know, are faraway suns, most of them bigger and brighter than the friendly neighborhood sun that lights our days. Our sun has been blazing away for billions of years and without a doubt it will go on blazing through billions of years into the future. The same holds true for the other starry suns in the night sky. So obviously nothing happens to them when our sun rises each morning. But where in the world are they during the daytime?        

This baffling mystery was not solved until people got a true picture of our Solar System. Before that, they thought that our little world was the very center of the Universe    and once every 24 hours, the entire Universe revolved around the planet Earth. This mistaken notion was set to rights some 400 years ago, by the great Polish astronomer, Copernicus.

A few years later, Galileo, the famous Italian astronomer, first observed the heavenly bodies through a telescope    and proved that the Copernicus theory of the Solar System was correct. It was quite a come¬down, when people had to face the fact that their Earth is not the center of the Universe. Actually, the sun is the central star of one of many solar systems in the endless Universe. The earth orbits around the sun, spinning around once every 24 hours as it goes.

Believe it or not, these facts are related to the appearance and mysterious disappearance of the stars in our sky. They do not., as people once thought, swing around to the other side of the earth. Every calendar day, the earth rotates on its axis turning first one side of the globe then another side to face the spacious universe that surrounds us on all sides.

During the day, our side of the globe faces the sun and we enjoy its dazzling daylight. At night our side turns away from the sun  ¬and we see the stars. Because the earth rotates toward the east, the starry constellations rise above the eastern horizon and march westward over the sky.

This starry parade continues all night and just before sunrise we still see a skyful of stars. But one by one the paler ones and finally the brightest ones wink out and disappear. Or do they? Actually they are still there in the sky, rising in the east and marching to set in the west. We just cannot see them.

This is because our starry sun casts its brilliant rays through the atmosphere above our heads. In a pitch dark room, even a small candle seems to shed a bright flame. But when we light a bright lamp, or let in the dazzling daylight, the little candle flame seems to fade and grow pale. The same thing happens to the daytime stars. When the sun rises, their tiny sparks of light are masked and lost in the razzle¬dazzle brilliance of its golden rays. We do not see them again until the sun and its brilliant glory sink to bed below the western horizon.