in 1963, American physicist and radio astronomer Arno Allan Penzias (born April 26, 1933) discovered cosmic microwave background radiation. Penzias's discovery of cosmic microwave background radiation helped establish the Big Bang theory of cosmology. Penzias and his partner, Robert Woodrow Wilson worked together on ultra-sensitive cryogenic microwave receivers, originally intended for radio astronomy observations. In 1964, upon creating their most sensitive antenna/receiver system, the Holmdel Horn Antenna, the two discovered a radio noise they could not explain. After further investigation, Penzias contacted Robert Dicke, who suggested it could be the background radiation predicted by cosmological theories, a radio remnant of the Big Bang. Penzias and Wilson won the Nobel Prize in Physics in 1978. NASA's work The Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) is a device designed to observe the transition out of the "cosmic dark ages" as the first stars ignite in nuclear fusion and the universe begins to resemble its current form. ARCADE consists of 7 precision radiometers carried to an altitude of over 35 km (21 miles) by a scientific research balloon. The device measures the tiny heating of the early universe by the first generation of stars and galaxies to form after the Big Bang. Sources of cosmic noise Cosmic noise refers to the background radio frequency radiation from galactic sources, which have constant intensity during geomagnetically quiet periods. Sun flares Cosmic noise can be traced from solar flares, which are sudden explosive releases of stored magnetic energy in the atmosphere of the Sun, causing sudden brightening of the photosphere. Solar flares can last from a few minutes to several hours. During solar flare events, particles and electromagnetic emissions can affect Earth's atmosphere by fluctuating the level of ionization in the Earth's ionosphere. Increased ionization results in absorption of the cosmic radio noise as it passes through the ionosphere. Solar wind Solar wind is a flux of particles, protons and electrons together with nuclei of heavier elements in smaller numbers, that are accelerated by the high temperatures of the solar corona to velocities large enough to allow them to escape from the Sun's gravitational field. Solar wind causes sudden bursts of cosmic noise absorption in the Earth's ionosphere. These bursts can only be detected only if the magnitude of the geomagnetic field perturbation caused by the solar wind shock is large enough. See also References Astronomical radio sources Noise