The Fermi Gamma-ray Space Telescope is a NASA observatory designed to reveal the high-energy universe in never-before-seen detail. With Fermi, astronomers have a unique tool to explore high-energy processes associated with solar flares, spinning neutron stars, outbursts from black holes, exploding stars, supernova remnants and energetic particles to gain insight into how the universe works.
Fermi detects gamma rays, the most powerful form of light. How powerful? The energy of visible light falls between 2 and 3 electron volts, but the gamma rays detected by Fermi have energies several thousand to billions of times greater.