Recently, in the New Year's Eve speech of the Chinese Academy of Sciences, Wu Xiangping, an astrophysicist and academician of the Chinese Academy of Sciences, introduced some popular science knowledge to everyone, and showed that he believed in the existence of extraterrestrial life, just like he said, if everyone does not believe in the existence of extraterrestrial life, then why go to where?
China's "Sky Eye" is currently the world's largest radio telescope, its completion and use so far has found a large number of pulsars, in fact, it also has a mission that is to search for the signal of extraterrestrial life. NASA's newly launched James Webb Space Telescope also has a search for extraterrestrial life on its future observation missions.
Most people believe that extraterrestrial life exists, but it can't be found at the moment! After all, the universe is so big, only 2-3 light-years diameter of the solar system human beings can not be fully explored, the farthest probe for more than 40 years to fly 23 billion kilometers, to fly out of the solar system at least 17,000 years.
There is no special way to search for extraterrestrial life, one is to launch unmanned probes for field exploration, the second is to launch manned probes to explore the field, and the third is to use various telescopes to receive signals from the deep space of the universe indiscriminately, and finally conduct differentiated research.
In this speech, Academician Wu Xiangping gave an example: He said that two months ago, astronomers used the 64-meter radio telescope of the Parks Observatory in Australia to receive a radio signal, which came from 4.2 light years away, and the frequency was 982MHZ, which was a narrow frequency signal and had a significant frequency shift, and human interference had been ruled out.
4.2 What's light-years away?
The mysterious alien signal received by Australian astronomers in 2019 is determined to come from 4.2 light-years away, and many people may not know much about what is at this distance, in fact, it is the first target of Voyager One to fly by, Solipita, why is it called Proxima Centauri? In fact, to put it bluntly, it is the neighbor of the solar system, it is the closest star to us, and the three-body civilization in Liu's science fiction masterpiece "Three-Body" was born from the nearest star.
Proxima Centauri and The South Gate Two A star and the South Gate Two B star belong to the triad star system, and Proxima Centauri is also the prototype in Da Liu's other science fiction novel "The Wandering Earth", and humans want to bring the Earth around Proxima Centauri. In fact, there were no planets around Proxima Centauri at the time of the novel' creation, but scientists later discovered a planet around Proxima Centauri that was in its habitable zone, known as Proxima b.
According to the current definition, a habitable planet needs to meet the needs of temperature, stable liquid water and air, then the proportion of planets in the habitable zone that meet these conditions is high. So it's good news to find planets in habitable zones around our nearest star, and it may actually be possible to spot extraterrestrial life on that planet.
With the help of telescopes to find mysterious alien signals from 4.2 light-years away, it is conceivable that a signal must be related to Proxima Centauri and its surrounding planets.
All the signals were collected by scientists in April 2019, and in June 2020, scientists conducted a collation and screening study of these signals, and just found this 982.002MHZ narrowband wireless signal, but in 2021, that is, more than two months ago, this mysterious alien signal was identified by scientists as some kind of radio interference on the surface of the earth, not as Academician Wu Xiangping said, which has ruled out human interference and determined to be the first alien call!
Do aliens exist?
As Academician Wu said, he believes that extraterrestrial life exists, otherwise there would not be so many countries and so many scientific research institutions looking for extraterrestrial civilizations, but the question returns to the beginning, such as the question of physicist Nobel Laureate Fermi" "Where are they?" This is the famous Fermi paradox. After all, the universe is so big, the Milky Way alone contains about 200 billion stars, and the sun is just an ordinary and inconspicuous member of it.
The diameter of the Milky Way is about 200,000 light-years, and the observable diameter of the entire universe is about 93 billion light-years, and if there is life only on Earth in such a large universe, it is completely impossible to say from a statistical point of view, even if the conditions for the birth of life are harsh and the probability is very low, but when the base is large enough, the results will be quite considerable.
At the same time, according to the current mainstream scientific view, the universe was born in the singularity of the Big Bang 13.82 billion years ago, which is enough for life to develop and evolve. For example, the earliest known life on Earth appeared 3.8 billion years ago, and after a long period of development and evolution, millions of species have appeared on The Earth today, and there has also been an intelligent civilization of humans.
Therefore, whether in terms of space or time, the probability of extraterrestrial life is relatively high.
Is there possible life around Proxima Centauri?
Due to technical limitations, we can't even complete the overall exploration mission of the solar system at present, so the closer we are to the object is enough to attract attention. The closest star to the Sun is Proxima Centauri, which is 4.2 light-years away, and there is a planet around this star, and it is in its habitable zone.
The mysterious signal received from Proxima Centauri in 2019 has made scientists increasingly interested in the nearest star. But can life really exist there? Scientists have come up with the idea that the habitable zones of red dwarfs are actually not as habitable.
Proxima Centauri is a red dwarf with a habitable zone of about 0.048 AU ( an average distance of 150 million km between the sun and the Earth ) , which means that Proxima B receives more radiation from Proxima Centauri. As a red dwarf, Proxima Centauri is not so stable, and various stellar activities often explode on a large scale, which causes a large number of high-energy particles to impact the celestial bodies around it from time to time.
Even if Proxima b has perfect habitable conditions at the beginning, under the violent impact of such high-energy particles, the atmosphere will gradually be stripped away, and the liquid water on the celestial body will be directly evaporated and become uninhabitable.
Say at the end
We think that the existence of extraterrestrial civilizations of extraterrestrial life is a fact that can be known from the reality of the situation, but where are they? Or how much life there is in the universe, these are uncertain, because the universe is too big, which is why we can't find each other! But with the advancement of human technology, we may receive more and more mysterious extraterrestrial signals, maybe they have always been there, but our equipment is not advanced enough to detect the existence of these signals.
This time, the signal 4.2 light-years away has been identified by natural scientists as Oolong, but Proxima Centauri is still fascinating to humanity.
Text/science black hole, image source network intrusion deletion.