Space Roar

The Space Roar is an anomalous radio signal first discovered by NASA's Goddard Space Flight Center via the balloon-borne ARCADE (Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission) instrument on July 22^nd, 2006, and formally announced on January 7^th, 2009 at the American Astronomical Society in Long Beach, California. The unexplained signal was found to be six times louder than the combined emissions of all known radio sources in the universe—sources which further analysis has likewise eliminated as potential origins for the signal.

ARCADE was initially designed for the purpose of observing heat signs from the earliest generation of primordial stars. The first instrument of its kind capable of detecting such a signal, ARCADE's precision and sensitivity is produced, in part, through the use of over 500 gallons of superfluid liquid helium; at 2.7° K, the instrument's temperature matches that of the cosmic microwave background, eliminating its potential to contaminate data received by ARCADE’s seven radiometers. Ironically, it was that accuracy which allowed ARCADE to perceive the Space Roar signal, the intensity of the noise effectively obscuring anything else it may have found.

Sources

1. _{"NASA Balloon Mission Tunes in to a Cosmic Radio Mystery" by Francis Reddy, NASA (January 7th, 2009)}
   
2. _{"Mystery Roar from Faraway Space Detected" by Andrea Thompson, SPACE (January 7th, 2009)}
3. _{"Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission" NASA}