Gammas from Heaven

Not long ago, physicists seeking to understand the cataclysmic events at the birth of the universe had to rely on massive, earthbound experiments in which beams of charged particles, steered by powerful magnetic fields, traveled in circles for miles before smashing into each other. Now, an increasing number of these particle physicists have turned to the skies, teaming with astronomers to launch spacecraft that can capture gamma rays from astrophysical processes with energies far greater than anything that can be generated in the most powerful atom smashers on Earth.