Fermi Gamma-ray Space Telescope (2008–present)

NASA's Fermi Gamma-ray Space Telescope has cataloged over 7,000 gamma-ray sources, discovering giant bubbles of energetic gas extending 25,000 light-years above and below the Milky Way's center. It also recorded the highest-energy photons—up to 1,000 times more energetic than those observed by typical gamma-ray observatories—from distant gamma-ray bursts billions of light-years away.