Cosmic noise

<p>Cosmic noise, also known as galactic radio noise, is radio-frequency electromagnetic radiation from sources <a href="/facts/Outer_space/R3LRKyFs">outside of the Earth's atmosphere</a>. Its characteristics are comparable to those of <a href="/facts/Thermal_noise/ur238TgX">thermal noise</a>. Cosmic noise occurs at frequencies above about 15 <a href="/facts/Hertz/6Wshj5qm">MHz</a> when highly directional antennas are pointed toward the Sun or other regions of the sky, such as the <a href="/facts/Galactic_Center/TI4MwWwM">center of the Milky Way Galaxy</a>. Celestial objects like <a href="/facts/Quasar/HS96328l">quasars</a>, which are super dense objects far from Earth, emit electromagnetic waves in their full spectrum, including radio waves. The fall of a <a href="/facts/Meteorite/NsmHlBlX">meteorite</a> can also be heard through a radio receiver; the falling object burns from friction with the Earth's atmosphere, ionizing surrounding gases and producing <a href="/facts/Radio_waves/XmB6WPpF">radio waves</a>. <a href="/facts/Cosmic_microwave_background_radiation/ThB2HkLS">Cosmic microwave background radiation</a> (CMBR) from <a href="/facts/Outer_space/R3LRKyFs">outer space</a> is also a form of cosmic noise. CMBR is thought to be a relic of the <a href="/facts/Big_Bang/I5T1vTnv">Big Bang</a>, and pervades the space almost homogeneously over the entire <a href="/facts/Celestial_sphere/TYAtXgor">celestial sphere</a>. The <a href="/facts/Bandwidth_(signal_processing)/7eMDzfJI">bandwidth</a> of the CMBR is wide, though the peak is in the microwave range.
</p>

Cosmic noise open-in-new

Cosmic noise