Randy Wilhelm, age 15, of Hutchinson, Kan., for his question:

WHAT EXACTLY IS A QUASAR?    7

A quasar is a galaxy that gives off enormous amounts of energy from its central area. Quasars radiate this energy in the form of light and radio waves. The word quasar is a shortened form of the term "quasistellar radio source."

Quasars were first observed in 1960 by astronomers at the Palomar Observatory near San Diego, Calif. By the mid 1970x, scientists had discovered about 500 quasars.

Some quasars are near the edge of the universe. It takes light, which travels 186,282 miles per second, about 10 billion years to travel from such quasars to earth. It is almost impossible to comprehend such a distance.

Scientists and astronomers estimmate the distance of a quasar by studying its brightness and its red shift. The red shift is a change in the light of a cosmic object toward the longer, or red, wave lengths of the object's spectrum or color pattern. It shows that quasars are moving away from the earth.