For decades, humanity has not lost hope of meeting its co-religionists in space. Scientists are building huge radio telescopes, volunteers are deciphering signals, but the search for alien civilization has not yet been successful.

Despite all the failures, there were also interesting cases. In 1977, the “Big Ear” radio telescope of Ohio University in the USA, while monitoring extraterrestrial signals, caught a transmission from the constellation Sagittarius, the source of which could be extraterrestrial beings. A few days after receiving the signal, astronomer Jerry Ehman, who discovered an interesting pattern, wrote “Wow!” in the margins of the printout. This reaction gave the name signal.

In 2024, scientists finally discovered Wow! Read about their discovery in the article 24 Channels.

Prehistory. What happened in 1977

In August 1977, the Big Ear radio telescope at Ohio University in Delaware, while monitoring the sky for extraterrestrial signals, recorded a signal from the constellation Sagittarius that, as it turned out, had signs of artificial origin.

This was actually determined by volunteer astronomer Jerry Eman, who examined the recorded data a few days later. The signal impressed him so much that Eman wrote “Wow!” in the margins of his computer printout. The scientist also identified the signal intensity indicators – the symbol 6EQUJ5.

Signal output / Ohio University

What was unusual about the signal? In 1959, scientists from Cornell University in the United States hypothesized that an advanced extraterrestrial civilization would send signals at a frequency of 1420 megahertz, which is emitted by neutral hydrogen. It is the most common element in the universe. The wow signal was broadcast at this frequency with a small error.

Although Wow! tried to find it dozens of times later, the signal was never noticed by any astronomers or volunteers. Although the discovery of the signal shocked the astronomy community, Ehman remained somewhat skeptical.

Even if there were sentient beings sending the signal, they would do it more than once. We should have seen it again after searching 50 times. Something tells me this is a signal from space debris bouncing off Earth.
– said the astronomer in 1994.

The source of the signal has also been suggested to be a hydrogen cloud accompanying one of two comets, 266P/Christensen and P/2008 Y2 (Gibbs), which flew across a section of the sky in 1977 at the same time the Wow signal was recorded.

Later, the scientist abandoned his skeptical view because later studies showed that the object that would reflect the signal from Earth would have to have unrealistic properties. Also, the signal frequency of 1420 MHz is hidden.

In a 1997 paper, Ehman wrote that he did not want to “draw large-scale conclusions from data that are not very large-scale,” acknowledging the possibility that the source could be another product of military or terrestrial sources.

Scientist in 2019: Wow! could be first signal from extraterrestrial intelligence

Interesting! A story featuring the “Wow!” signal. It was used in the TV series “The Three-Body Problem”, based on the book of the same name by Chinese author Liu Qixin. In the plot, the signal was also received from a Chinese radio telescope – a printout with the code 6EQUJ5 is held by the series’ protagonist Ye Wenjie.

The content of the signal is a warning to Earth not to communicate with humans or extraterrestrial beings.

What was it: new research results

Interest in the “Wow!” signal has not faded in the 2020s. A team led by astrobiologist Abel Mendez from the University of Puerto Rico in Arecibo, home to the world’s second largest radio telescope, has been busy studying the mysterious message.

A new hypothesis suggests that the source of the signal could be a super-powerful cosmic laser — but it’s not a weapon from an alien civilization, but a natural object.

Our latest observations, conducted between February and May 2020, revealed similar narrowband signals near the hydrogen line, although less intense than the original Wow! signal.
Mendes explains.

The 1977 signal was an extremely powerful burst of radio waves near the 1420 MHz hydrogen line that lasted only 72 seconds. Although scientists had decided in 1959 that the hydrogen could be a “greeting” from another civilization, Wow! contained no decipherable modulation and never repeated itself. That’s why Mendez and his team decided to search for the signal’s natural source.

Specifically, the scientists searched for bursts of short-band radio waves similar in frequency to the Wow signal in archived data from the now-defunct Arecibo Observatory’s Red Dwarf Radio Emission Project (REDS).

Scientists have found four interesting recordings, all from the vicinity of the small red dwarf Stellar Tea Garden, located just 12.5 light-years away.

Teegarden’s star / NASA visualization

Signals from around Teegarden’s Star are associated with interstellar clouds of cold hydrogen, scientists have discovered. This points to a potential source of Wow! A powerful burst of radiation passing through the cold hydrogen cloud excites the gas to produce a powerful pulse of radiation near 1420 MHz.

The result of such a process would be a natural astrophysical microwave laser, or maser, emitting an intense concentration of narrow-band light in the hydrogen line that would look like a Wow signal from a distance.

Interesting! Despite the hypothesis that the signal is natural, Teegarden’s Star could still be home to another civilization. In 2019, the Calo Alto Observatory discovered two Earth-like planets in the stars’ habitable zone, where liquid water could exist.

Teegarden’s Star, a red dwarf, is unlikely to produce a flash powerful enough to cause a burst of radiation as powerful as Wow!, but there are other cosmic objects that are poised to do so. For example, neutron stars, which have extremely strong magnetic fields. Magnetars. Or another type of star – soft gamma repeaters, which periodically emit gamma or X-ray radiation. Scientists from Arecibo also emphasize that such emissions are rare, which explains the uniqueness of the 1977 signal.

Our hypothesis takes into account all observed features of the Wow! signal, represents another source of false positives in the search for technosignatures, and suggests that this signal is the first recorded outburst of an astronomical maser in the hydrogen line.
– says the report.

Were there contacts with other civilizations?

Throughout the history of searching for signals from extraterrestrial civilizations in the 20th and 21st centuries, in addition to Wow!, there have been several candidates for “technosignatures,” messages from artificial extraterrestrial beings. These include:

• BLC1 signal from Proxima Centauri, the closest star to the Solar System. Recorded in 2020;
• Discovered in 2003, the near-hydrogen line signal SHGb02+14a originates from a point between the constellations Pisces and Aries;
• fast radio bursts of unknown nature and signals from pulsars and quasars.

However, none of the listed signals contain all the hallmarks of a technosignature.

Despite conflicting or completely implausible stories about aliens and UFOs, humanity has never had contact with other space civilizations. This explains the Fermi paradox, proposed by Italian physicist Enrico Fermi in 1950. In short, the paradox looks like this:

The widespread belief that there are many technologically advanced civilizations in space is not supported by observation and is paradoxical. Therefore, either human understanding of nature or human observations are incomplete and fallible.

The history of the paradox is as follows – in 1950, during a lunch with his colleagues, Fermi asked, “Where is everyone?”, referring to aliens. It happened during a visit to the Los Alamos National Laboratory. Scientists joked about aliens allegedly stealing their garbage cans.

According to scientists, it is very easy to explain the incomprehensible with the intervention of extraterrestrial beings, but it is not clear where there is convincing evidence for the existence of extraterrestrial beings. The result was the idea that there may be other civilizations but they are very far from each other, or that the only civilization in a deserted area of ​​​​space is Earth. This explains the silence of the universe.