Sorry, But Chinese Scientists Didn’t Actually Find an Alien Radio Signal

Manasee Wagh
·5 min read
2
Photo credit: Jeff Dai/Stocktrek Images - Getty Images
Photo credit: Jeff Dai/Stocktrek Images - Getty Images

  • A Chinese radio telescope detected radio signals that researchers said could be technological traces of an alien civilization.

  • The Five-hundred-meter Aperture Spherical Radio Telescope (FAST) in Guizhou, China, detected the signals.

  • Astrophysicists were excited about the possibility of finding a true alien technosignature, but it was ultimately interference from Earth-based electronics.

China reported this week that the most powerful ground-based radio telescope may have identified technological traces of an alien civilization in an electromagnetic signal from space. The Five-hundred-meter Aperture Spherical Radio Telescope (FAST) in southeast China picked up the narrow-band signal, typical of an artificial source and not a natural one, such as a black hole or stars. But it was too good to be true.

What researchers actually found was radio-frequency interference originating on Earth, likely from cell phones, computers, satellites, or any number of other electronics located near the observatory. All of these devices produce weak radio transmissions of their own.

FAST’s unique ability to scan in 19 different directions of the sky helps eliminate signals coming from more than one direction at a time, astronomer Vishal Gajjar tells Popular Mechanics in an email. An alien signal would originate from a single point in the sky. In fact, this technique eliminated 99 percent of the signals in this particular survey, says Gajjar, who is project scientist for the SETI (Search for Extraterrestrial Intelligence) Institute’s Breakthrough Listen project at the University of California, Berkeley. One percent of signals had to be studied more carefully.

“As one of the co-authors of this study, I can firmly say that these are not likely to be alien in origin. The found signal was checked with all details and we found that it was not actually coming from the sky but likely to be generated by our own Earth-based technology,” he says.

Astrophysicist Sascha Trippe of Seoul National University in South Korea, who is not involved with FAST, didn’t expect that possible signs of aliens would turn out to be real, either. Ahead of the researchers’ final analysis, he tweeted his skeptical response to the news of the possible alien signal discovery:

Researchers check every potential signal in detail, Trippe tells Popular Mechanics in an email. “For example, you check if the signal indeed originates from the direction of one, and only one, specific star.”

FAST is the world’s largest and most sensitive single-dish radio telescope. Located in Guizhou, in a mountainous region of China, it sits in a natural, bowl-shaped depression. Among its applications in observing pulsars, stars, and other natural space phenomena, FAST also scans for very low, narrow-band radio frequencies in its quest for alien signals in the vast sea of electromagnetic waves from both Earth and space.

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That’s because—among other reasons—a narrow-band frequency rules out natural astrophysical sources of radiation as well as Earth’s atmospheric “noise,” says Trippe. FAST targets exoplanets, those planets that are outside our own solar system. In September 2020, it officially launched its search for extraterrestrial civilizations in collaboration with SETI’s Breakthrough Listen project. Since then, researchers from Beijing Normal University, the National Astronomical Observatory of the Chinese Academy of Sciences, and the University of California, Berkeley, have been working together to search for alien civilizations. They discovered two groups of signals from space that year, but determined they were not from aliens.

While scientists that use the telescope were hopeful this time, they knew the detection of a real alien presence was unlikely. “The possibility that the suspicious signal is some kind of radio interference is also very high, and it needs to be further confirmed or ruled out. This may be a long process,” Zhang Tongjie, chief scientist of the China Extraterrestrial Civilization Research Group told Science & Technology Daily in a June 14 news report from the official newspaper of China’s Ministry of Science and Technology.

The analysis turned out to be a short process, as by June 15, astronomers had checked each signal thoroughly and knew they were looking at a false alarm, says Dan Werthimer, who helped install the SETI Institute detectors on FAST. He also directs UC Berkeley’s SETI radio telescope, which searches for alien signals. “These signals are from radio interference; they are due to radio pollution from earthlings, not from ET,” he tells Popular Mechanics in an email, referencing the lovable alien from Steven Spielberg’s eponymous 1982 film, E.T. the Extra-Terrestrial.

“All of the signals detected by SETI researchers so far are made by our own civilization, not another civilization,” he adds.

SETI has been searching for some sign of aliens since 1984, and it has grown into a worldwide effort. FAST may be the next natural choice for radio astronomers looking for signs of aliens, after the retirement of the Arecibo Observatory Telescope in Puerto Rico.

Also known as the Tianyan telescope, translated as “Sky Eye,” FAST has three major advantages over Arecibo in searching for extraterrestrial civilizations, Beijing Normal University astrophysicist Zhang Tongjie tells Science & Technology Daily: the ability to monitor a larger sector of the sky and twice the sensitivity, as well as the ability to check signals from 19 different points in the sky. Plus, telescope operators can change the positioning of its 4,500 aluminum panels as needed through remote computer control.

Keep your eyes peeled for more updates from Pop Mech about how researchers would handle a positive identification of an alien signal—and what they would do if a realistic candidate for an alien signature emerges from all of the radio pollution one day.

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