For more than six years, NASA's Fermi Gamma-ray Space Telescope has scanned the sky for the highest-energy light in the universe—gamma rays. Since the spacecraft’s launch, researchers have cataloged more than 3,000 discrete gamma-ray sources. Now, major improvements to methods used to process observations from Fermi have yielded an expanded, higher-quality set of data that allows astronomers to produce the most detailed census of the sky yet made at extreme energies. A new map of the gamma-ray sky reveals 12 gamma-ray sources with energies exceeding a trillion times the energy of visible light, along with 48 sources never before seen. The highest-energy sources, which are all located within our galaxy, are mostly the remnants of supernova explosions and pulsar wind nebulae, places where rapidly rotating neutron stars accelerate particles to near the speed of light. Watch the video for a tour of the new map.