We have been listening to space waiting for a message for decades. Organizations like SETI are analyzing unusual radio signals for possible transmission from an intelligent extraterrestrial civilization. But what will happen when she really contacts us? When will we hear something that we expect and not at the same time? Almost 40 years ago, radio astronomer Jerry Eiman scanned a patch of sky in the hope of finding a signal from an alien civilization. And suddenly he caught something. The signal was incredibly short, a flash, but it produced a separate jump in the diagram - a kind of instant transmission. After printing, Eiman circled the splash with a red pen and wrote one word: "Wow!"
The Wow! Signal, as it was called, was never explained, and nothing of the kind was heard later. But an organization called the Search for Extraterrestrial Intelligence Institute (SETI) continued to listen to the airwaves in search of signals that could be generated by intelligent life forms in the galaxy and beyond.
What happens if SETI hears this signal? How do we confirm that the transfer was made by the aliens? Not so long ago, a story flashed in the media about how the astronauts of the Apollo 10 mission heard strange "space music" in their headphones while on the far side of the moon. Scientists believe the event was solely due to radio interference. However, this episode once again raised the question: how do we distinguish one cosmic sound from another in our search for signs of life?
“They constantly hear and drop something,” says John Elliott of Leeds-Beckett University in the UK. "It's very rare that something gets to the target group after being discovered."
This so-called Post-detection Task Group at SETI is a small council of scientists who analyze interesting radio signals detected by radio telescopes around the world. Elliott is his dick - and he spent a lot of time wondering what it would be like if we discovered an extraterrestrial radio wave.
He has been with the organization since 1999, and during that time, the target group has only evaluated one signal every couple of years or so. There are many detections every day, but they are quickly dismissed as interference or artificial signals. Messages can come from anywhere. There is even a network of volunteers with their own successors, the Seti League, who do their own work.
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“If there is a repeating signal, it’s interesting,” Elliott explains. "Then we would wonder if this repetitive signal exhibits complexity, if someone can send me language, mathematics, or some information."
We are unlikely to understand what the aliens are saying right away - but perhaps we will work and find out.
SETI has a list of “possible signals” as well as a Rio Scale system for classifying the significance of any signal. The ranking is built depending on the characteristics of the signal, how it was detected and where it came from.
The Apollo 10 astronauts have remembered and preserved "space music" for many years. Their case only recently went public, in 2008, when NASA released a recording of the incident.
Any really interesting signals received by SETI will go public - but not before a rigorous verification process is carried out. In fact, SETI has a specific list of detection protocols for such events. It also includes the dissemination of data so that it can be analyzed by third parties. Dan Wertheimer of the University of California, Berkeley - also a member of the Post-detection Task Group - notes that the group is wary of possible hoaxes.
“It could be a software bug or a prank of the student idiots, so our goal is to get independent confirmation,” he says.
The interest in any possible extraterrestrial signals will obviously be enormous. In 2004, astronomers had to cool down the hype about erroneous reports of the detection of an "alien signal". Last year, SETI picked up a series of "fast radio bursts" that made scientists think. An intelligible explanation was never found for them, which led to thoughts about extraterrestrial civilizations.
But then how could one be convinced of this? Among the most important points is the distance covered by the signal. Obviously, if he bounced off a satellite or space debris in Earth's orbit, he would not indicate extraterrestrial communications. To perform this analysis, SETI must analyze its own recordings from another telescope.
“When you have two telescopes looking for a signal, you can triangulate and measure the distance to determine if the signal is nearby or not,” says Wertheimer. But this has not been done urgently. "We have never had such a situation where we let the director of the observatory and say: we need your telescope now."
Another question that worries Elliott and many others is what to do if a signal is detected, how to answer it if we really consider it to be created by an extraterrestrial civilization. Do we want to answer at all?
According to the SETI protocol, "no response to a signal or any other manifestation of extraterrestrial intelligence should be sent until appropriate international consultations have taken place."
“There is still no consensus on what to do - the two main camps, respectively, are in favor of yes, answer, and no,” says Elliott, adding that we will miss the opportunity if we do not try to answer.
But another problem remains - how to communicate without having a common language? We will have to find and define signals that will be common for both civilizations in the Universe.
“We can point to phenomena that civilization will be aware of and use that as a key to starting a dialogue,” he says.
This can mean naming a general signal representing a "star" or "galaxy", or counting celestial bodies, for example. But we need to take into account the delay in transmissions - the nearest star system with a planet 10.5 light years away. It will take 21 Earth years to send and receive a signal.
Dan Wertheimer says that all the "interesting" signals are still unexplained, such as fast radio flares and the Wow! Signal, or are caused by natural phenomena such as supernovae. But he is optimistic and thinks that the universe is filled with life. The earthlings only need to enter the game. Some time will pass and we will find out the degree of our loneliness.