Ruth Moore, age 13, of Rockland, I11., for her question:

WHAT IS A TEKTITE?

A tektite is a glassy stone that may look like a teardrop, ball, disk, rod, button or dumbbell. Most tektites measure from 1/2 inch disk, 4 inches in length. They are black, dark brown or dark green.

Scientists say tektites were formed when giant meteorites or comets crashed into earth. The blast melted the soil and splashed drops of liquefied rock over great distances. These drops then hardened and fell to earth as tektites.

Other scientists say the drops resulted when impacts on the moon blasted large chunks of material through space into orbit around the earth.

These chunks then broke into smaller pieces that melted and solidified again while falling to earth.