What are the benefits of installing a radio telescope behind the moon?



The moon always points the same side to the earth side, and people on the earth can not see the other side of the moon. In 2019, a small Chinese satellite takes a photo of the moon viewed from the back, or a huge giant metal mass of 2000 trillion tons is reported to be sleeping, and the back of the moon is attracting attention However, some astronomers are interested in installing a radio telescope behind the moon.

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Unlike optical telescopes that observe visible light, radio telescopes capture radio waves emitted from astronomical objects. Radio telescopes are a great weapon to unlock the secrets of the universe, because even if they are objects as far as they can not be observed by optical telescopes or even dark objects, they can be observed by receiving radio waves and analyzing them by a computer.

However, there are weak points in radio telescopes, for example, because the ionosphere in the upper layer of the atmosphere has the property of reflecting radio waves, it reflects part of radio waves from space, and radio waves from earth activity etc. It may disturb observation. In addition, radio waves emitted by human activities are also obstacles to radio telescopes, and in the past there were cases where the identity of the mysterious signal observed by radio telescopes was 'microwave range'.

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Many radio telescopes are designed to capture frequencies from hundreds of MHz to hundreds of GHz , and radio waves below 100 MHz are considered 'low frequencies' in the field of radio astronomy . On the earth where various obstacles exist, the telescope can not observe radio waves below 30 MHz.

Therefore, the bottom of the moon is the place to hit to observe low frequency radio waves that are difficult on earth. On the other side of the moon, various radio waves emitted from the earth are always blocked by the moon body, and no disturbing noise is introduced. Also, since there is no ionosphere that blocks radio waves from space, it is an ideal location for a radio telescope.

In recent years, interest in low frequency radio waves emitted from space has increased. Jack Burns, an astrophysicist at the University of Colorado, points out that it could help to gain a better understanding of the early universe of the radio telescope installed behind the moon. Radio waves emitted by the early universe are redshifted due to expansion of the universe when they reach the earth, so it is likely to be important to observe the low frequency band of 10 to 50 MHz when observing the early universe. .

Mr. Barnes has launched a satellite called DAPPER in the moon's orbit, and is promoting a project to observe radio waves from space on the other side of the moon. However, it is necessary to use thousands of antennas at the stage of collecting more data, and it is more practical to install antennas on the moon instead of on orbit in the next step. 'The moon is stable,' Barnes stated that it would be ideal to set up a radio telescope on the other side of the moon for observation.

by bertomic

in Science, Posted by log1h_ik