Radio Telescope


Many instruments have been created and manufactured with the aim of being able to study and analyze what happens in space. One of these objects is known by the name of radio telescope , a very important device that makes it possible to capture the different radio waves that are transmitted by all celestial bodies . It should be noted that radio waves are the wavelengths that have a wavelength within the electromagnetic spectrum that is longer even than infrared light.


What is a radio telescope?

The radio telescope is a device that serves to capture all the radio waves that are generated and are generated by the celestial bodies which are emitted as a type of radio frequency signal by means of a parabolic antenna.



The radio telescope is a device or instrument that is used in order to receive and locate the different radio waves that come from outer space. They are a kind of large antenna that has been manufactured to effectively intercept the different radio emissions that occur on a star or in a specific galaxy.


Characteristics of a radio telescope

Among the main characteristics that we can find in the radio telescope, the following are mentioned:

  • It has a radio receiver and a complex antenna system capable of capturing radio frequency radiation.
  • Its shape varies as well as its size , this will depend on the type of waves that must be collected.
  • They are considered the largest telescopes in the world.
  • It is a type of directional radio antenna .
  • His field of study is known by the name of radio astronomy .
  • It can pick up different kinds of radio waves .
  • It uses one or more parabolic antennas to be able to do its function.

What is a radio telescope for?

The radio telescope is a device that is used to carry out studies and analysis on the radio light that occurs naturally in galaxies, stars, in black holes and in practically any type of astronomical object. It is in charge of being able to capture all the radio waves that are born from the celestial bodies


The radio telescope had its origin in 1931 when Karl Guthe Janksy , an engineer, managed to find a signal that increased in intensity with the passing of days. He dedicated himself to analyzing and studying this signal, concluding that the signal had practically the same duration as the period of rotation that the Earth had, this indicated that the place where the signal came from was at a point on a celestial body. fixed . Later he made a series of analyzes, concluding that the signal came from the Milky Way.


The first radio telescope as such was created in 1930 by Karl Jansky , a radio engineer who worked for the Bell Telephone Laboratories who had in his hands the task of investigating the natural radio signals that cause interference in transatlantic telephone communications.

He built it as a kind of antenna made with tin tubes which he mounted on the wheels of a Ford T. This antenna managed to rotate every 20 minutes and thus performed a scan on the horizon and then recorded the signals with a moving pen. or to listen to the signals with headphones.

During his measurements, he managed to find a sound similar to a radio hiss that came from the sky every day and this sound could not be precisely located by his invention, so he concluded that the signal came from space . Jansky exhibited his work at various meetings throughout 1933, and the story made the front page of the New York Times.

The first radio telescope that was manufactured as such, was in the hands of an engineer of American nationality called Grote Reber , this in 1937 . Since that time, many scientists and engineers have been manufacturing these devices to achieve a greater wavelength range .


The inventor who created the first radio telescope, a 9 meter antenna, was Grote Reber in 1937.

Parts of a radio telescope

The parts with which a radio telescope is built are the following:

  • Antenna : the antenna can be very basic made with a metal dipole or it can be more powerful like the parabolic antenna. In the latter case, a mathematical form is used that makes the incoming radio waves bounce off the same place, which is known as a focus. When the antenna is parabolic, it usually has several receivers in order to be able to tune in to multiple frequency channels.
  • Plate : this part is responsible for collecting all the radio signals that come from space to focus them on an antenna. The larger the plate, the more waves can be collected.
  • Receiver : this part is in charge of being able to take the radio waves that are received in the antenna and then convert them into electrical signals or voltages. This part of the radio telescope must have a high and adequate sensitivity.
  • Detector : it is responsible for making measurements regarding the power density of the electrical signal.
  • Analyzer : this part is usually formed by a device that is connected to a computer in order to be able to take the data and form an image from it.

How does it work

Radio telescopes work thanks to a large reflector plate that is used to collect and concentrate the different radio waves . As the Earth rotates, the dishes can be moved in order to find the origin of the source , making it possible for the radio telescope to measure the different signals from a certain point and for a long period of time. These receivers are responsible for registering the different signals and converting them into frequencies so that later the computers to which they are connected can synthesize the information to result in acomplete image of the object to which it has been observed.

Featured radio telescopes

There are several important radio telescopes located in strategic positions. The most important ones are listed below.

  • FAST : this radio telescope is spherical in shape and has an aperture of approximately five hundred meters. It is located in China , in Pingtang County. It is located within a natural depression to give better support to the dish and its surface is continuously adjusted to give rise to a satellite dish aligned with the sky.
  • ALMA : it is located in the Atacama desert in Chile and is the largest radio telescope in the world and is also considered one of the most innovative and revolutionary instruments in the field of astronomy . It is a telescope that is composed not only of one device but also of 66 different high-precision antennas and with it, extremely important information has been obtained, including an image of the ring that exists surrounding HL Tauri, a star located 450 light years away. In addition, it has managed to discover complex molecules in MWC 480.
  • Arecibo Radio Telescope : It is located on the north coast of Puerto Rico and is located within a land depression. It is the largest single dish radio telescope in the world and has an area of ​​305 meters in diameter. It is responsible for collecting radio astronomical data and observations of celestial bodies .

SETI project

This project, whose name means Extraterrestrial Intelligence Research, began in 1959 using radio signals to find intelligent life in outer space . To do this, it uses a series of radio telescopes which are located in different places around the world in order to be able to track the sky and be able to make observations on the different radio waves that can be sent by extraterrestrial beings.


Its importance lies in the fact that thanks to these devices it is possible to carry out studies on the radio frequencies that come from space, which in turn allows to determine the place from which the different radio waves arise and to carry out studies on them. It is also widely used to analyze and study radio signals of extraterrestrial origin.

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