Call Dr Arroway, because NASA has detected a deep space sound that defies belief or any explanation. They don't have a single clue about its origin, according to Alan Kogut from the Goddard Space Center:
The universe really threw us a curve. Instead of the faint signal we hoped to find, here was this booming noise six times louder than anyone had predicted.
According to NASA, "the source of this cosmic radio background remains a mystery". It's not primordial stars, it's not any known radio source, and in fact, the problem here is that there is "not enough radio galaxies to account for the signal". In other words, nothing in the known cosmos is capable of producing this deafening sound. University of Maryland at College Park's Dale Fixsen-part of NASA's ARCADE team- says, that to get this kind of signal, "you'd have to pack [radio galaxies] into the universe like sardines. There wouldn't be any space left between one galaxy and the next". So in more scientific terms: They don't have a flying frak about what the hell this may be.
The sound has been detected by ARCADE, a balloon-borne probe which is chilled to 2.7 degrees above absolute zero. The instrument itself is inside a tank of 500 gallons of liquid helium to reach that temperature, which is the same temperature as the cosmic microwave background radiation. [NASA]