Number 201 (Story #1), November 3, 1994 by Phillip F. Schewe and Ben Stein VERY ENERGETIC COSMIC RAYS are scarce. Studies over many years indicate a decided dropoff at energies above 10**20 eV. Previously only two definite cosmic-ray events at this energy had been recorded. Now a third---with an energy of 1.7-2.6 x 10**20 eV---has been recorded, at the Akeno Giant Air Shower Array (AGASA) in Japan. Astronomers there suspect that the cosmic ray originated outside our galaxy but could not have traveled more than about 100 million light years owing to the energy that would be lost to the universal background radiation en route. The AGASA detector, which samples the shower of particles engendered by the cosmic-ray particle in the upper atmosphere, could determine the incoming angle to within one degree on the sky. Taking into account the effect of the intergalactic magnetic field, the cosmic ray's starting point was assigned to a location at the edge of the Pisces galaxy cluster, a place where no active galactic nucleus (a likely engine for so powerful a cosmic ray) is known to reside. (N. Hayashida et al., Physical Review Letters.)