Five billion years ago, a blazar abruptly flared, triggered an intense rain of gamma rays. Racing across the universe for millennia, they finally slammed into NASA’s Fermi satellite over several days this June, setting a new record for the most luminous high-energy object we’ve ever seen.
Sometimes a strange signal comes from the dark and it takes a while to figure out what that signal means. In this case, scientists analyzing high-energy gamma rays emanating from the galaxy's center found an unexplained source of emission that they say is "consistent with some forms of dark matter."
NASA's Fermi Gamma-ray Space Telescope is an observatory in low Earth orbit that the Agency uses to study some of the most high-energy sources of radiation in the Universe. Its wide-eyed Large Area Telescope (LAT) makes a sweep of the entire sky every three hours, soaking up gamma rays that emanate from cosmic…