History

History of the radio telescope

History of the radio telescope

The radio telescope is an astronomical observation device used to capture the radio waves emitted by some celestial bodies. This is the case of active pulsars or galaxies, which emit radiofrequency radiation. These radiations are easier to detect through the radius of the electromagnetic spectrum than through the region of visible light, captured by conventional optical telescopes.

Most radio telescopes use a satellite dish to amplify the waves. This allows astronomers to contemplate the radio spectrum of a certain region of the sky. Two or more radio telescopes can also be used together and combine the signals they receive from the same source. In this way, astronomers can more accurately distinguish the source of radiation.

The first radio telescope that has been reported was built by the American engineer Grote Reber in 1937. Since then several different types of telescopes have been developed for a wide range of wavelengths, both radio and gamma rays. Reber's radio telescope was nine meters long. Only 20 years later, in 1957, it was surpassed by the Jodrell Bank radio telescope, which measured 76 meters.

Currently, the world's largest single radio telescope is the Russian RATAN-600, which has a circular antenna of 576 meters in diameter. Radio telescopes are also used in projects such as SETI (Search Extraterrestrial Intelligence), the search program for extraterrestrial intelligence, or in the monitoring of unmanned space flights.

Radio astronomy

The study of the radiations emitted by celestial bodies is called radio astronomy. It is a branch of astronomy through which it is possible to "observe" (obtain data from) bodies and situations that are impossible to detect with optical astronomy.

In the field of radio astronomy, to obtain good signals you must use large antennas or several groups of antennas that work in parallel. When two or more radio telescopes are properly combined, they can form a large radio telescope. The technique to combine them and analyze the set of radio signals they receive is called radiointerferometry.

Arecibo radio telescope

One of the most popular radio telescopes in the world is Arecibo, located in Puerto Rico. Famous for having appeared in numerous movies and television series, the Arecibo telescope stands out for its large size. Its main antenna has a diameter of 305 meters and is built within a depression. Its converging antenna is the largest and most curved in the world, with a great capacity to receive electromagnetic waves.

There are several significant scientific discoveries of the Arecibo radio telescope. On April 7, 1964, Gordon H. Pettengill's team determined that Mercury's rotation period was not 88 days, as previously believed, but only 59 days. In August 1989, the photo of an asteroid, 4769 Castalia, was first made. A year later, Polish astronomer Aleksander Wolszczan discovered the pulsar PSR B1257 + 12, which would later help him find his two orbital planets. It was the first extra-solar planets to be discovered.

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