Kris Janssen, age 17, of Dallas, Texas, For her question:

What is the fourth state of matter?

The material of our everyday world is either solid, liquid or gaseous and for ages WE took it for granted that there were only these three states of matter. Without knowing it, WE had introduced ourselves to a fourth state. It is the rare mixture of charged gases inside a neon tube. Then the space age began and experts sampled material from far above the Earth.

This fourth state of matter is ca11ed plasma. It is a dynamic mixture of gaseous fragments and teeming energies, somewhat like a neon tube on a grand scale. It now is suggested that still other states of matter may Exist under the tremendous heat and pressure of the Earth's interior.