“Within the past year or so the merest glimpse has been obtained of the universe as revealed by the very-high-energy photons called gamma rays. The glimpse has been provided by fewer than 100 energetic photons, recorded by a gamma ray ‘telescope’ carried into orbit on April 27, 1961, by the artificial satellite Explorer XI. It is doubtful whether such a small number of particles have ever before been analyzed so intensively in an effort to extract information about the universe. The analysis is still continuing in a laboratory at the Massachusetts Institute of Technology.”

Scientific American, May 1962

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