China's Sky Eye searches for aliens

During the May Day holiday, the touching story of the guardian of the "China Sky Eye" attracted attention. In the years since it was put into use, the "China Sky Eye" has achieved a number of scientific results with international influence, but some unpopular professional terms have also made the public "unclear and impressive". Let's change to a lighter topic: Can the "China Sky Eye" help us find aliens?

"China's Sky Eye" specifically refers to my country's 500-meter Aperture Spherical Radio Telescope, which is the world's largest single-aperture radio telescope. It has achieved many technological innovation breakthroughs and can conduct extensive exploration of the deeper and more marginal parts of the universe.

The "China Sky Eye" in Guizhou

How do we search for aliens? If we use the most direct method - launching deep space probes to actively search the boundless interstellar space, it is obviously a long and laborious project. You may think that humans use radio waves to transmit information and achieve long-distance communication. If we can obtain radio waves emitted by other celestial bodies and try to analyze regular signals, we may be able to find alien civilizations.

In the 1930s, American radio engineer Jansky discovered a set of repeated radiation signals of unknown origin while investigating background noise. His research results confirmed that celestial bodies can emit radio waves, thus promoting the birth of radio astronomy, which is the discipline of observing celestial bodies by receiving electromagnetic waves in the radio frequency band.

In order to receive radio waves from the universe, radio telescopes came into being. Simply put, radio telescopes are mainly composed of antennas and receivers, and their work process can be summarized as follows: receiving radio waves → amplifying signals → recording and analyzing results. Among them, antennas are used to collect weak electromagnetic signals in the universe. Commonly used parabolic antennas can reflect electromagnetic waves and converge them to a common focus, so that they can be detected by the receiver, further amplify the signal, separate the noise, and finally display the processed signal on the terminal device. Optimists imagine that radio telescopes can "listen" to the sound of the universe around the clock, and even communicate with aliens.

With the rise of radio astronomy, countries have built radio telescopes and observatories one after another, and the "China Sky Eye" ranks among the best in the world. Experts believe that the "China Sky Eye" has three major advantages in searching for extraterrestrial civilizations: a larger observation area, twice the sensitivity, and 19 beams that receive signals from different areas of the sky.

According to public information, when the "China Sky Eye" was first planned, its scientific goals included searching for possible interstellar communication signals and extraterrestrial civilizations. To this end, the "China Sky Eye" is equipped with back-end equipment specifically for searching for extraterrestrial civilizations, which can filter out useful narrow-band candidate signals from the massive amount of signals received and exclude celestial bodies and artificial signals. In addition, the "China Sky Eye" has joined the international SETI search for extraterrestrial civilizations program, using powerful radio telescopes and globally networked computers to continuously promote the exploration of extraterrestrial civilizations and the mysteries of the universe.

In September 2020, the "China Sky Eye" officially launched the search for extraterrestrial civilizations, mainly conducting synchronous sky surveys and exoplanet target observations, and has discovered suspicious signals more than once. Of course, the subsequent scientific research team will need to spend energy and time to retest and identify to eliminate possible interference.

Do aliens exist? This question has long troubled mankind and has become one of the core driving forces for human exploration of the universe. With the continuous upgrading of large scientific facilities for deep space exploration such as the "China Sky Eye", I believe we will have more opportunities to uncover the mysteries of alien life in the future.

Interestingly, humans are clearly not psychologically prepared to face extraterrestrial civilizations. After all, fear comes from the unknown. Perhaps, as depicted in the science fiction novel The Three-Body Problem, we will receive a "three-warning" message from another world in the universe: Don't answer. (Author: Huang Yanru)