History of Radio Astronomy

History of Radio Astronomy

Radio astronomy, an important branch of astronomy, studies celestial bodies through their emissions in the domain of radio waves.

In the late 1920s, a young American engineer, Karl Jansky, was working in Holmdel (New Jersey) to investigate the causes of radio disturbances of atmospheric origin that intervene with long-distance transmissions.

Jansky built an antenna formed by a cage-shaped metal structure and suspended it on the wheels of an old Ford, so that a motor could rotate the antenna in different directions.

Then a long and patient data collection work began, recording the various types of radio noises captured at different wavelengths, but especially in short waves and from various directions in the sky.

The results of this work indicated the existence of three types of interference: short discharges from local storms; analogous discharges corresponding to very distant storms: persistent whistles coming from a mysterious source in regular movement across the sky.

After months of intense research, Jansky arrived in the spring of 1932 to conclude that the source of that noise was located in the constellation Sagittarius: in the direction of the core of our Galaxy.

The news caused great commotion among the public and multiple conjectures were made about the origin of those signals: however, Jansky himself, who was not an astronomer, realized that there was nothing mysterious about them. He understood that many celestial bodies, in addition to radiating energy, in the form of visible light, also do so in the form of radio waves.

A new astronomical research instrument was born. which offered the possibility of studying the celestial bodies not only through the telescope, but also through the radio antennas: those that were later called a radio telescope.

Maybe the times were not mature enough for the new science to develop, but the truth is that Jansky's request to build a new Paraboloid-shaped antenna to deepen the studies was not addressed. It is often the case that managers have little vision.

But the investigations of the young engineer of Bell Telephone were taken by another American, Grote Reber, who can be considered as the first and authentic radio astronomer in the world.

However, only after World War II and thanks also to the developments of Radar technologies, radio astronomy could finally take off, leading astronomers to discover a new Universe.

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