In 1977, the Big Ear Radio Telescope at Ohio State University picked up a strong narrowband signal from space. The signal was a continuous radio wave that was very strong in intensity and frequency and had many expected features of an extraterrestrial transmission. This event would be known as the Wow! Signal, and remains the strongest candidate for a message sent by an extraterrestrial civilization. Unfortunately, all attempts to identify the source of the signal (or to detect it again) have failed.
This led many astronomers and theorists to speculate on the origin of the signal and what kind of civilization could have sent it. In a series of recent articles, amateur astronomer and science communicator Alberto Caballero offered some new ideas about Wow! Alien signal and intelligence in our cosmic neighborhood. In the first article, he studied nearby Sun-like stars to identify a possible source of the signal. In the second, he estimates the prevalence of extraterrestrial civilizations hostile to the Milky Way and the likelihood of them invading us.
Nearly fifty years after it was detected, the Wow! The signal continues to tempt and challenge the explanation. In recent years, attempts have been made to attribute it to comets on the edge of our Solar System, an explanation that the astronomical community has since rejected. In 2020, interest in this candidate ETI signal was revitalized when Cabellaro identified a Sun-like star near the sky where Wow! Signal detected. If the analysis is correct, this famous signal may have come from a Sun-like star 1,800 light-years away.
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The summary, the Wow! The signal was detected by the now defunct Ohio State University Radio Observatory (called the “Big Ear”), which was assigned to SETI surveys in 1973 after completing an extensive survey of extragalactic radio sources. In the summer of 1977, astronomer Jerry R. Ehman was volunteering with the project and was commissioned to analyze the massive amounts of data printed on line paper. On August 15, it detected a series of values indicating a massive increase in intensity and frequency.
Ehman circled the alphanumeric designation of this sign (6EQUJ5) and wrote “Wow!” next to. In recent years, coinciding with the 35th anniversary of the signal detection, interest and research in this mysterious event has been renewed. This should come as no surprise, given how he remains the most likely candidate for an extraterrestrial message. Despite being (by all accounts) an unmodulated continuous wave, there were several indications at the time that the signal was not of natural origin.
On the one hand, the signal was only heard on one frequency, with no noise detected on any of the other 50 Big Ear radio channels. This is incompatible with natural broadcasts, which cause static at other frequencies, while the Wow! The signal was narrow and focused: what we expected from a transmitted radio signal. Second, the signal “went up and down” for the 72 seconds it was detectable. This is consistent with space signals, which increase in intensity as they move across the sky and closer to the telescope’s radio, and then decrease as they move away from the telescope.
Third, the signal was observed near 1420 MHz, a “protected frequency” at which terrestrial transmitters are prohibited from transmitting, as they are reserved for astronomical studies. All this indicated that the signal was of extraterrestrial origin, as satellites and terrestrial radio sources would have been repeating in nature, while the Wow! The signal seemed to be a one-time event. Based on the time and orientation of the Big Ear telescope, astronomers deduced that it must have come from somewhere in the direction of the constellation Sagittarius.
The mystery of Wow! The signal has long been the subject of interest by Alberto Caballero Díez, a Spanish exoplanet hunter, SETI researcher and science communicator. While Caballero studied Criminology at the University of Santiago de Compostela in Spain, he has since focused his efforts on the investigation of habitable exoplanets and extraterrestrial intelligence. He has even relied on one of his hobbies (daily trading) to fund his efforts to search for extraterrestrial intelligence (SETI).
Perhaps best known for hosting The Exoplanets Channel, a Youtube channel about exoplanet studies, SETI, and interstellar travel. He is also known for coordinating the Habitable Exoplanet Hunting Project (HEHP), an international network of professional and amateur astronomers dedicated to studying exoplanets in nearby star systems. In particular, the project hopes to find potentially habitable exoplanets around G (yellow na), K (orange na) or M (red na) stars that do not explode 100 light-years from Earth.
“The project is a global network of professional and amateur optical observatories looking for potentially habitable exoplanets around nearby stars, using the transit method,” Caballero told Universe Today by email. “I founded the project in 2019. [S]Since then, more than 30 observatories on five continents have joined forces. “
In 2020, HEHP announced the discovery of an exoplanet the size of Saturn orbiting the habitable zone of its parent star. This was the first discovery of exoplanets made entirely by amateur astronomers. It was also in 2020 that Caballero observed a Sun-like star almost identical to our Sun (a solar analog) as he searched for the sector of the sky where Wow! Signal detected. Caballero described this discovery through The Exoplanets Channel (episode below) and in an article * published in the International Journal of Astrobiology in early May.
In this article, Caballero studied nearby Sun-like stars using data from ESA’s Gaia Observatory (compiled from the Gaia Archive) and determined the most likely source. The survey contained a sample of 66 G-type yellow dwarfs (similar in size and spectra to the Sun) and K-type orange dwarfs (slightly smaller and fainter than the Sun). It reduced it to a candidate star located about 1,800 light-years from the Solar System. This was 2MASS 19281982-2640123, a perfect solar analog comparable in size, mass, and spectra to the Sun. As Caballero said:
“When searching the ESA’s Gaia Archive for stars with mass, radius and luminosity similar to the Sun. I discarded red dwarfs because a large percentage of them emit flames that destroy exoplanetary atmospheres, and from the data we don’t know which ones of them are Bengal stars “.
The similarities between this star and our Sun make it the most likely place to find life and a possible civilization (as we know it). At the same time, the distance is consistent with previous research by Italian astronomer Claudio Maccone. In 2010, Maccone conducted a statistical analysis ** where it concluded (with 75% confidence) that the nearest ETI would be 1,000 to 4,000 light-years away. As Caballero explained, this makes 2MASS 19281982-2640123 an ideal candidate for potential techno-signature tracking search engines.
These conclusions raise another interesting point, which goes directly to the heart of the whole “listen or send messages” debate (also known as SETI and METI). While SETI’s efforts are to listen to the cosmos for signs of possible extraterrestrial transmissions (“passive SETI”), extraterrestrial messaging intelligence (METI, or “active SETI”) is to compose messages that are transmitted to the Internet. ‘space. In that sense, Wow! The signal is a perfect example of passive SETI efforts, while the Arecibo message is a perfect example of active SETI or METI.
In his second + article, Caballero addresses this issue by conducting a statistical analysis of possible civilizations hostile to our galaxy and the possibility that one or more of these detect signals from Earth (and possibly choose to invade). Because radio antennas and radars constantly filter signals into space, Caballero felt that a risk assessment was needed. As he explained, this was to use the last century of Earth’s history as a template, a century full of conflicts:
“I based my estimate on the frequency of invasions on Earth over the last 100 years. Only 51 countries out of 195 invaded another country. I discovered that as time goes on and humanity develops, the frequency of By extrapolating the results to humanity once it becomes a type 1 civilization capable of interstellar travel, the frequency and therefore the probability of invasion decreases.Estimates are based on life as we know her. “
In addition, Caballero directed this same analysis toward humanity and the possibility that we could become a “malicious civilization” once we have become a Kardashev-type civilization. A civilization at this level of development would be able to harness all the energy of its planet and limit a measure of interstellar travel to nearby stellar systems. His analysis showed that a maximum of four malicious civilizations would be within the reach of our transmissions. As Caballero said, this indicates that an alien invasion is not the greatest existential threat facing humanity:
“The estimated low risk, lower than the probability of the impact of a planet-killing asteroid, could support METI’s efforts. SETI is necessary, but it’s like looking for a needle in a haystack. If we really want to be able to “We need to start transmitting laser messages to thousands of exoplanets. Whether we do it or not depends on what the international community says.”
Statistically speaking, METI may not be the existential risk that some say it could be. Probably nothing more than threats that are …