Supernova Remnant Imaged in Gamma Rays . ... With up to a billion times the energy of ordinary "medical" x-rays , they easily penetrate telescope lenses and mirrors, making it very difficult to create gamma-ray images of cosmic sources. Still, an array of large telescopes designed to detect gamma-ray induced atmospheric flashes - the HESS ( High Energy Stereoscopic System ) experiment - has produced this historic, resolved image of a supernova remnant at extreme gamma-ray energies . ...