radio emission

astronomy

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Last updated

July 13, 2026

Quick Summary

In astronomy, a radio source is an object in the universe that emits significant amounts of radio waves. These emissions can be either continuum radiation, covering a broad range of wavelengths, or line radiation, emitted at specific wavelengths.

Continuum radiation is generated by thermal processes or synchrotron emission, where electrons spiral in magnetic fields. Line radiation, such as the 21-centimeter line from hydrogen, is crucial for studying the composition and motion of interstellar clouds and galaxies.12

Prominent radio sources include pulsars, quasars, and radio galaxies. The discovery of cosmic microwave background radiation in 1965 provided evidence for the big-bang model.12

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radio telescope
Extraterrestrial radio emission was first reported in 1933 by Karl Jansky, an engineer at the Bell Telephone Laboratories, while he was searching for the cause of shortwave interference. Jansky had mounted a directional radio antenna on a turntable so that he could point it at different…
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Extraterrestrial radio emission was first reported in 1933 by Karl Jansky, an engineer at the Bell Telephone Laboratories, while he was searching for the cause of shortwave interference. Jansky had mounted a directional radio antenna on a turntable so that he could point it at different…
Read More

Jupiter
Radio emission
Jupiter was the first planet found (in 1955) to be a source of radiation at radio wavelengths (see radio and radar astronomy). The radiation was recorded at a frequency of 22 megahertz (corresponding to a wavelength of 13.6 metres, or 1.36 decametres) in
Read More
Jupiter was the first planet found (in 1955) to be a source of radiation at radio wavelengths (see radio and radar astronomy). The radiation was recorded at a frequency of 22 megahertz (corresponding to a wavelength of 13.6 metres, or 1.36 decametres) in
Read More