Jeff Flowers, age 8, of Montgomery, Alabama, for his question:

What do they mean by artificial satellites?

An artificial flower is a copy of a real flower. An artificial satellite also is a copy of something. The most famous real satellite is the golden moon. It is a satellite because it orbits in a path that goes around and around the earth. You might say that it belongs to the planet earth, because the earth's gravity stops it from escaping and zooming away into space. The moons that belong to giant Jupiter and the other planets also are satellites.

Long ago we learned that the earth's gravity holds our satellite moon in captivity, Space Age scientists learned how to copy this idea. Of course a man made artificial satellite is not as big as the real moon satellite. But it too orbits around and around the earth. It is sent aloft just high enough for the earth's gravity to hold it in captivity. It travels just fast enough so that gravity won't bring it down before it does its task. It behaves like a real moon satellite and because it is man made, we call it an artificial satellite.