Cosmic antimatter.

Examines rare and elusive antiparticles which may hold clues to some of the mysteries of astrophysics. Actions taken by scientists to search for antimatter in cosmic rays; Collisions which produce pairs of pions, unstable particles that quickly decay into positrons, electrons, neutrinos and antineutrinos; Antimatter detectors which have found a maximum abundance of only one antiproton for every 10,000 protons in the rain of cosmic rays.