Photo de stock - Dec. 12, 1971 - Telltale Tracks. Cosmic rays - Cosmic rays - mysterious particles that bombard the solar system from all directions in space - left these tracks in a piece of plastic (top), a mineral sample (middle), and a fragment of glass (bottom). A special array of these detector materials will be carried to the moon and back next March by the Apollo 16 astronauts. The tracks recorded by the detector array are expected to provide new information about the age, composition, and origin of cosmic rays, the most powerful of which are generated by unknown sources in space. The experiment was designed - under NASA sponsorship - by scientist at the General Electric Research and Development Center, Schenectady, N.Y., the University of California at Berkeley, and Washington University, St. Louis, Mo. The compact detector array, which weighs just over eight pounds, was engineered and fabricated by GE's Space Sciences Laboratory in Philadelphia, Pa. (Credit Image: © Keystone Press Agency/Keystone USA via ZUMAPRESS.com)