This radio has always been silent: 30 years ago, the search for signals from extraterrestrials began regularly.

Exactly 30 years ago, the SETI Institute was established and launched one of the most ambitious programs for the search for extraterrestrial life, the Phoenix Project. In February 1995, the young and determined Jill Tarter arrived at the largest (64 m) radio telescope in the Southern Hemisphere (the Parkes Telescope, Australia). The team brought with them unprecedented equipment, but immediately faced a problem: Australian butterflies were drawn to the bright screens and disrupted the settings. Despite having a fantastic telescope, persistence, and a well-thought-out methodology, the project ended like many others. "It seems we live in a desert neighborhood," the scientists declared.

This was not the only attempt to find aliens, but perhaps the most thoroughly considered. Today, we repeatedly echo the words of physicist Enrico Fermi, spoken in the summer of 1950 in the cafeteria of the Los Alamos lab: "Listen, really, where is everybody?"

FROM TESLA TO PULSARS

By that time, the history of attempts to find intelligent radio signals spanned more than a decade. Hardly had people gained access to radio when they wondered: could this device be used to communicate with other worlds? In Alexei Tolstoy's novel "Aelita," a barely audible call from Mars, muffled by static, beckons one to embark on a journey. Yet long before this book, Nikola Tesla claimed he had captured messages from Mars.

During World War II, radars became essential: this spurred the advancement of technology. The first breakthrough was the detection of solar noise (natural). Today, anyone with a satellite dish can pick it up, but at that time, it was a significant advancement. By the 1960s, radio telescopes were able to observe subtle phenomena such as relic radiation (the "echo" of the Big Bang) and pulsars (these periodic signals were initially mistaken for coveted alien Morse code).

In 1959, an article appeared in Nature: we were already capable of capturing messages from civilizations of "our" level. The article recommended listening at a wavelength of 21 cm, where interstellar hydrogen emits. This was supposedly a standard wave, understandable to all. Perhaps it was a mistake, as hydrogen creates noise and is more likely to interfere. But there were no other ideas at that time.

In 1960, the search focused on nearby stars (the Ozma project), and in 1971, NASA initiated the famous SETI program. One thousand five hundred radio telescopes! 10 billion dollars in funding! The project (which was not realized in that form) included both listening to their messages and sending our own. In 1974, a radio message was sent to the M13 cluster, 25,000 light-years away. An answer would come in 50,000 years!

It is clear that such actions were aimed more at the public than carried any scientific significance. By 1995, SETI had effectively collapsed. American authorities mocked the "search for little green men," but in reality, they found almost nothing (see Appendix).

Private funding saved the initiative from collapse. This is how the SETI Institute and the Phoenix Project came to be.

ONLY INTERFERENCE

It was a year of great hopes. Free from government funding, the enthusiasts who created the private SETI Institute believed that now, without bureaucrats, everything would work out! The institute was led by the aforementioned Jill Tarter.

Initially, the Phoenix Project aimed to use several radio telescopes around the world. However, they were "undergoing modernization" (in essence, the SETI Institute was gently turned down). As a result, only the Parkes telescope and another one, located 200 km from the main site to filter out terrestrial noise, participated in the project.

In February 1995, the Parkes telescope was directed towards a nearby (49 light-years away) star in the constellation of Phoenix (a southern constellation not visible from our location). In total, 209 stars were observed. The search bandwidth was often expanded.

As a result, the project detected 148,000 signals, of which all but 39 turned out to be terrestrial. Upon further investigation, it was revealed that even those 39 were from satellites. And that's the end of the story.

30 years ago, regular searches for signals from aliens began

Photo: Shutterstock.

WHAT IS SEEN AND HEARD

The search continues. They are looking even now.

In 2015, the Breakthrough Listen project was launched. The strategy changed: they now listen to distant galaxies as well. In 2019, they even stumbled upon something (see Appendix).

Volunteers were recruited for signal analysis. People download an application onto their computers, and it works autonomously, requesting fresh signals and analyzing them. Over the years, 5 million volunteers have consumed electricity worth a billion dollars. And even though each individual paid only a few cents for "light," this figure indicates that humanity has already invested significantly in the search.

The telescopes involved in the SETI Institute projects can detect an airfield radar from a distance of 200 light-years. This means that there are no airfield radars at that distance.

What are the reasons for the failures? Answering this question would require a good book. While some scientists pin their hopes on a new generation of radio telescopes, others argue that aliens do not use radio at all. And some believe that advanced civilizations do not last long and destroy themselves. Others suggest that we are immersed in an artificial world created by "them," but "they" are in no hurry to reveal themselves. Perhaps they are afraid (stick your neck out and you’ll be eaten), or maybe Earth is "their" experiment.

Radio is not the only avenue of search. For instance, there is an active search for astroengineering objects, something that appears natural but is actually artificially created. Yet, for some reason, there is still a desire to catch the first intelligent signal through radio. It’s romantic. Perhaps it will be so?

APPENDIX

All (almost) strange radio signals received by humans

Nikola Tesla regularly captured "intelligent messages from Mars" in 1900. It remains unknown what they were. Theories suggest they were secret, experimental transmissions by Marconi for transatlantic communication, or natural noise from Jupiter. The situation is complicated by the fact that Tesla's "receiver" was essentially a mechanical device, and reproducing it today for verification is challenging.

In 1927, Jørgen Hals noted that the signals he sent returned as if they were being picked up at approximately Mars' orbit, amplified, and sent back to him. This phenomenon was dubbed the World Echo, and it has never received a clear explanation. Interestingly, it is (almost) no longer observed today. If the cause was natural, where did it go?

In 1977, a primitive (and now decommissioned) radio telescope detected a single strong signal, dubbed "Wow!" because that’s what the operator wrote in the margins of the printout. Despite various "explanations," it remains the most likely candidate for the first contact. Its interpretation is complicated by the fact that the telescope's antenna was stationary, and we do not know how long it actually lasted; the signal is simply numbers on tape (the "audio" on the internet is a fake); the operator checked the tape once a week, and when the signal came in, there was no one at the telescope.

In 2012, the SETI project received a signal from the exoplanet KOI 817. Opinions were divided. The nature of the message was undoubtedly artificial. Some claimed the source was our own satellites, while others insisted that something had finally happened.

In 2019, the Breakthrough Listen project detected something near the closest star, Proxima Centauri. Last October, director Simon Holland, citing a "leak" from the project, claimed that "we have already found them," and this would be announced "by the end of 2024." As we know, that did not happen. The signal is now considered interference from a satellite.

In 2024, Harvard astronomer Avi Loeb stated that the so-called "fast radio bursts," discovered about a decade earlier, are "exhaust" from the operation of alien ion engines.

COMMENTS

What does science say?

Oleg Uglov, Senior Researcher at the Institute of Space Studies of the Russian Academy of Sciences

- We found nothing because it is very difficult. From the very beginning, few believed in the success of the enterprise