Is there any extraterrestrial civilization in the vast universe? Is there an alien with a big head, big eyes and a small chin hiding somewhere in the dark? It's a question that has crossed almost every modern mind at one time or another, and it's not just a science fantasy. It's a question that serious science is trying to crack.
More than a decade ago, astronomers discovered a mysterious type of radio waves from outside the Milky Way galaxy. These radio waves, which flash for just a few milliseconds, are capable of emitting the energy that the sun emits throughout the day, eclipsing many celestial bodies in the universe. Astronomers call these radio astronomical phenomena of unknown origin fast radio bursts.
Is this a signal sent to Earth by aliens? Some people put forward the basis of judgment: millisecond radio pulse, the arrival time and direction of the earth is relatively random, some directions have repeated signals, some directions have periods, and no corresponding celestial bodies were found, may be a means of communication of extraterrestrial civilization.
The idea has reignited a heated debate about extraterrestrial civilizations: "FRBs are from alien civilizations," "FRBs are a call from aliens," "FRBs are aliens knocking on the door," and so on. And so on. A search engine in China for the keywords "fast radio bursts" and "aliens" yielded more than 560,000 messages.
One group of people who participated in the discussion was very cautious in expressing their opinions, citing only the evidence. They are scientists at the forefront of human exploration of the unknown. Recently, an international team led by the Huiyan Satellite Research Team at the Institute of High Energy Physics of the Chinese Academy of Sciences obtained the latest observational evidence pointing to the source of FRBs. But it turned out, to the disappointment of some, that it wasn't an alien knock on the door.
FRBs were first detected in 2007. Since then, scientists have detected hundreds of them from different locations in the sky, and observed repeated bursts coming from the same direction.
"Fast radio bursts occur very frequently in the universe, and it is estimated that at least tens of thousands of them reach Earth every day." Researcher at the institute of high energy physics, Chinese Academy of Sciences, "eye" satellite chief scientist Zhang Shuangna tells a reporter, before the latest findings, with accurate positioning rapid radio bursts from the distant universe beyond the Milky Way, the origin and causes of the mysterious outbreaks, become one of the greatest puzzles in astronomy today.
Scientists have proposed more than 50 possible origins of FRBs, including the merger of two compact stars, the collapse of compact stars, the explosion of magnetars, the collision of neutron stars with asteroids, and so on. Some scientists have linked them to extraterrestrial civilizations, presumably sending signals from aliens, and this has added a romantic twist to the scientific search for FRBs.
As research on FRBs has become more plentiful, the mystery of their origin has become more contentious, with different factions of people arguing about their origins.
Of course, it's not just a war of words, and scientists are doing everything they can to get closer and closer to FRBs. Of course, there are all kinds of telescopes, such as the visible light telescope, the Hubble, but also other X-ray telescopes, gamma ray telescopes, and so on.
In Zhang's view, there are two keys to figuring out what causes FRBs: first, finding the corresponding celestial body; second, seeing the FRBs emit at other wavelengths and limiting their physical mechanism.
"To put it bluntly, it's to see if there's any other signal coming out of the FRB, but over the years, you can 'look hard' through a telescope in the direction of the source and find nothing." Zhang Shuangnan said.
Adding to the mystery, the idea that the bursts originate from aliens has reignited speculation.
On 28 April 2020, at 2.34pm GMT, an extremely bright fast radio burst, known as FRB 200428, was simultaneously observed by the Canadian Chime experiment and the US STARE2 experiment. Intriguingly, this FRB burst occurred in roughly the same direction as a magnetar in the Milky Way.
So could this magnetar be the source of a fast radio burst that might be home to aliens?
The quest for extraterrestrial civilizations doesn't stop there. Since the FRBs come from magnetars, how do you prove that the magnetars are not home to aliens?
Researcher at the institute of high energy physics, Chinese Academy of Sciences, vice "eye" satellite ground application system, the total teacher Song Liming explanation: magnetar is a strong magnetic field of neutron star, only about 10 km radius, the quality is equivalent to three the sun, its strong magnetic and gravity, the surface has no atmosphere, so do not have biological survival conditions, it is difficult to life.
He told reporters that the discovery demonstrates the strong scientific capabilities of the satellite as a space observatory. An interesting detail is that the "eye" satellite positioning accuracy is significantly higher than that detected the same quick radio bursts of two other radio telescopes, Zhang Shuangna team submitted paper, paper reviewers said "don't believe that such a high precision data", the team had to write lengthy explanation, to dispel the doubts of the referees.
Song Liming also revealed that ExTP, known as an enhanced version of the "Insight", is on the way to development, which is a large international cooperative space X-ray astronomy satellite project led by China. In the study of neutron stars, black holes and other celestial bodies, its comprehensive performance has been improved by more than an order of magnitude compared to the international similar satellites. It is expected to further bring China's space high-energy astronomy research into the international leading level.
"Extragalactic fast radio bursts will have very faint high-energy counterparts due to their greater distances, and ExTP will be an ideal device to detect them in the future, promising even greater discoveries." "Song Liming said.
So, can the current research completely rule out FRBs and extraterrestrial civilizations?
In Zhang's view, FRB 200428 certainly did not originate from extraterrestrials, and the possibility of other FRB bursts coming from extraterrestrials cannot be completely ruled out at this time, but the possibility is relatively small because the characteristics of other FRB bursts are consistent with that of FRB 200428.
"From a rigorous scientific point of view, we cannot completely rule out the possibility of any existence in space," he told reporters. "But the partial solution to the FRBs' origin mystery will greatly reduce the probability and necessity of searching for extraterrestrial life and FRBs, and the scientific community to explore the relationship between the two." Romantic speculation about aliens may also be dashed.