The ‘Wow’ signal is probably not from aliens after all The ‘Wow!’ signal may not be from aliens at all
But in reality, the search for extraterrestrial intelligence (also known as SETI) is much harder. In reality, searching for extraterrestrial life (also known as SETI) can be a difficult task. Astronomer Jerry R. Ehman, who was reviewing the data, wrote “Wow!” and gave this signal its nickname.
“The Wow! The signal is intriguing to me, because up until now nothing has come close to explaining what it means. Seven Rasmussen explains that it’s the exact frequency you would select if you wanted to send a long-distance radio wave through space. “It’s my favorite possible technosignature,” the authors add. The Wow! signal has yet to be detected again, leaving astronomers wondering what caused this weird observation.
[ Related: How scientists decide if they’ve actually found signals of alien life ]
The Wow! The signal is represented by “6EQUJ5”. Ohio History Connection has preserved the original printout of Ehman’s exclamation. Credit: Public Domain
Astronomers use all wavelengths (radio included!) of light to study the cosmos. To study the universe, astronomers use all wavelengths of light (radio included!). Radio waves, for example, enabled the first ever image of a Black Hole a few decades ago. Radio waves also helped Jocelyn Bell Burnell to discover a strange dead star called a pulsar and revealed disks that act as nurseries for the planets orbiting other stars. A narrowband radio signal is one type of technosignature, a sign of intelligence or technology beyond Earth. While nature produces a lot of broadband signals, the technology can produce very focused messages. It could be an art piece, a tool, a habitat or a message. Rasmussen says that we’d have to prove it couldn’t happen naturally. “Nature can create right angles (pyrite, bismuth, all manner of crystals), but not, say, a house.”
Scientists also consider a variety of technosignatures other than radio images, from the sci-fi concept of a Dyson sphere harnessing a whole star’s energy to more relatable technological effects like pollution in a planet’s atmosphere. The idea of alien radio signals has been ingrained in our collective memory, as seen in the movie Contact when Jodie Foster uses old-fashioned headphones to listen to a radiotelescope. It’s important to note that real radio telescopes do not work that way- there’s no Lightning port for plugging in earbuds. Some astronomers continue to search for radio technosignatures, including a repeating of the Wow! Signals from the direction Sagittarius are being searched for by astronomers, such as the Breakthrough Listen Project. Radio telescopes used include the Allen Telescope Array (in California) and the Green Bank Telescope (in West Virginia). But none of these surveys has yet found anything more convincing than Wow! The signal was narrowband, and it occurred at a wavelength that is interesting, perhaps deliberately chosen: 21 centimeters. This wavelength corresponds to one of the lines for atomic hydrogen, which is the most abundant element in the universe. Natural astrophysics can explain the Wow! A group of international astronomers has recently published a preprint in which they combed through the data archives of Puerto Rico’s Arecibo Observatory. This observatory was once the largest single-dish telescope in the entire world, but it collapsed catastrophically in 2020. The astronomers found signals that were similar to Wow! but they could attribute them easily to clouds of hydrogen circling between stars. They suggest, therefore, that the Wow! Rasmussen describes this as “the most compelling hypothesis I’ve heard, but I’d like to find the magnetar/SGR responsible for the maser before I say it was definitely a natural phenomenon.” Rasmussen calls this “the most compelling theory I’ve ever heard,” but he’d first like to identify the magnetar/SGR that caused the maser. The signal itself.
