Scientists from the University of Delaware have discovered very high energy gamma rays in the Cigar Galaxy (M82), a bright galaxy filled with exploding stars 12 million light years from Earth. The gamma rays observed by the team have energies more than a trillion times higher than the energy of visible light and are the highest-energy photons ever detected from a galaxy undergoing large amounts of star formation. The findings provide strong evidence that exploding stars are the origin of the cosmic rays that bombard our atmosphere.