Allen Burdette, age 8, of Charleston, Wcst Virginia, for his question:

What are space orbits?

Most of our words ca me down to us from older languages. What they meant before often helps us to understand better what they mean now. The orbit came from an older word which meant the rut left by a wheel track. Such a track shows the path of a wheel or wagon.

Our word orbit also means a path. But it is not the path of a round wheel. Instead it is the path of a round orb or sphere, a heavenly body such as the sun, the moon or a planet. Each of these heavenly bodies races through space around its own path, or orbit.

In 1968, the first man‑made moons were launched. They too became heavenly bodies, solid objects hurtling through the heavens. They too had orbits, paths which took them around and around. The orbits of the man‑made moons, like the orbit of the real moon, were out in space around the earth. The earth's orbit is around the sun.