s73-36162

S73-36162 (November 1973) --- Dr. Robert S. Clark changes magnetic tape on the Radiation Counting Laboratory's mini-computer. The computer calculates the total content of radioactive isotopes in the lunar materials. Some 120 different samples from the six landings on the moon have been studied by the lab's gamma spectrometer, which generates 65,000 individual data points of each sample. Measurements of radioactive isotopes reveal how long they have been near the surface, and also reflect how much the rocks have been eroded by micrometeorites. Photo credit: NASA