The latter became apparent rather quickly. Since then, scientists have looked to see where the radiation is coming from while looking to describe the properties of the signal. So the surprise was gradually revealed over months.' That said, the impact was still huge. 'It then took months of data analysis to first separate instrumental effects from the signal and then to separate galactic radiation from the signal. 'While it might make a good movie to see us surprised when we see the light meter pop over to a value six-times what was expected, we actually spent years getting ready for our balloon flight and a very busy night taking data,' said NASA scientist Dale J. It was then that the intensity of one particular signal became apparent, albeit over many months. By looking at all of the 'light' and comparing it to a blackbody source, ARCADE was able to see the combination of many dim sources.

This was different from typical radio telescopes, which observe and contrast two points in the sky. ARCADE was able to make 'absolutely calibrated zero-level' measurements, which means it was measuring the actual brightness of something in real physical terms rather than relative terms.

Where is the sound coming from