![]() This noise complicates efforts to detect the very first stars, which are thought to have formed about 13 billion years ago - not long, in cosmic terms, after the Big Bang. The sought-for signal from the earliest stars remains hidden behind the newly detected cosmic radio background. The plane of our galaxy, the Milky Way, runs across the center. The observed region is colored on this all-sky radio map. "There wouldn't be any space left between one galaxy and the next."ĪRCADE viewed about 7 percent of the sky. "You'd have to pack them into the universe like sardines," he says. The problem, notes team member Dale Fixsen of the University of Maryland at College Park, is that there don't appear to be enough radio galaxies to account for the signal ARCADE detected. ![]() Similar emission from other galaxies creates a background hiss of radio noise. In 1931, American physicist Karl Jansky first detected radio static from our own Milky Way galaxy. Many objects in the universe emit radio waves. The source of this cosmic radio background remains a mystery. "Instead of the faint signal we hoped to find, here was this booming noise six times louder than anyone had predicted." Detailed analysis ruled out an origin from primordial stars or from known radio sources, including gas in the outermost halo of our own galaxy. "The universe really threw us a curve," Kogut says. In July 2006, the instrument launched from NASA's Columbia Scientific Balloon Facility in Palestine, Texas, and flew to an altitude of 120,000 feet, where the atmosphere thins into the vacuum of space.ĪRCADE's mission was to search the sky for heat from the first generation of stars. The finding comes from a balloon-borne instrument named ARCADE, which stands for the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission. A team led by Alan Kogut of NASA's Goddard Space Flight Center in Greenbelt, Md., today announced the discovery of cosmic radio noise that booms six times louder than expected. Listening to the early universe just got harder. The noise is six times louder than expected. The balloon-borne ARCADE instrument discovered this cosmic static (white band, top) on its July 2006 flight. A mysterious screen of extra-loud radio noise permeates the cosmos, preventing astronomers from observing heat from the first stars.
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