In 1932, while attempting to determine the source of static interference in radio communication systems, American engineer Karl Jansky (1905-1945) discovered the existence of radio waves emanating from beyond the Earth. Jansky traced all but one of...

In the 1960s a Cambridge University radio astronomer named Martin Ryle (1918-1984) discovered ways to combine the information from several radio telescopes to simulate a much larger instrument. These advances in radio astronomy helped pave the way for...

Before 1931, astronomers could gain information about the cosmos only by visual means, using the naked eye aided by magnifying lenses and reflective mirrors. In the early part of the twentieth century, however, a new way of assessing the nature of the...

By measuring regions of the electromagnetic spectrum not available to optical astronomers, radio astronomy effectively extends the range of astronomical observation. During the twentieth century, radio astronomy advanced to become one of the most...

Since radio astronomers first tuned into the skies, scientists have listened for an elusive radio signal that would confirm the existence of extraterrestrial life. One of the major efforts in the last quarter of the twentieth century was a project...

Study of celestial bodies by measuring the energy they emit or reflect at radio wavelengths. It began in 1931 with Karl Jansky's discovery of radio waves from an extraterrestrial source. After 1945, huge dish antennas, improved receivers and...

Radio astronomy is a subfield of astronomy that studies celestial objects in the radio frequency portion of the electromagnetic spectrum. Radio astronomy techniques are similar to optical techniques but radio telescopes have to be much larger due to the...