Priscilla Landt, age 13, Of Spokane, Wash., For her question:

What is Operation mohole?

Operation mohole could be as important as our orbiting satellites. It is a daring project for drilling through the earth's crust for samples of the dense mantle below. The top of the mantle is a tacky or plastic layer some 500 yards thick. This is called the Moho. Operation mohole will. Drill through the Moho to the mysterious mantle below and, we hope, bring forth priceless new information about the solid globe on which we live.

Experts suspect that earthquakes and other upsets in the earth's crust are caused by forces in the deep mantle. The government is working with many business concerns to make the valuable mohole project possible. A good place to drill is off our Pacific Coast. Here the crust below the sea is very thin, and the Moho layer is only about five and one half miles below the surface of the sea.