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Radio astronomy is the study of celestial phenomena through measurement of the characteristics of radio waves emitted by physical processes occurring in space. Radio waves are much
longer than light waves. In order to receive good signals, radio astronomy
requires large antennas. Radio astronomy is a relatively new field of astronomical research.
History
Nikola Tesla in the Colorado Springs lab recorded cosmic waves emitting from interstellar clouds and red giant stars. He
observed repeating signals conducted by his transciever. He announced that he received extraterrestrial radio signals. Tesla
stated that he received signals from planets in some of the scientific journals of the time. The scientific community did not
believe him, primarily because research of cosmic signals did not exist (what is known today as radio astronomy), and the
community of science rejected Tesla's data. Tesla spent the latter part of his life trying to signal Mars.
One of the earliest modern investigations into extraterrestrial sources of radio waves were by Karl Guthe Jansky, an engineer with Bell Telephone Laboratories, in the early 1930s. The
first object actually detected was the center of the Milky Way, followed by the
sun. After World War II, substantial
improvements in radio astronomy technology were made by astronomers in Europe and the United States, and the field of radio
astronomy began to blossom.
Developments
Radio astronomy has led to substantial increases in astronomical knowledge, particularly with the discovery of several classes
of new objects, including pulsars, quasars
and radio galaxies. Such objects represent some of the most extreme and
energetic physical processes in the universe.
Radio astronomy is also partly responsible for the idea that dark matter
is an important component of our universe; radio measurements of the rotation of galaxies suggest that there is much more mass in galaxies than has been directly observed (see Vera Rubin). The cosmic microwave background radiation was also first detected using radio telescopes.
However, radio telescopes have also been used to investigate objects much closer to home, including observations of the Sun and solar activity, and radar mapping of the planets.
The United States government has established an institution to conduct radio astronomy research, titled the National Radio Astronomy
Observatory (commonly abbreviated as NRAO). This institution controls various radio telescopes around the United States
included the world's largest fully mobile radio telescope, the Green Bank Telescope. The United States government has also set aside a national radio quiet zone for
radio astronomy research centered around Green
Bank, West Virginia. As a result, Green Bank is now the home of NRAO's primary
facility.
See also: Very Long
Baseline Interferometry
External links
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