Scientists from the SETI Institute, Berkeley SETI Research Center, and the International Center for Radio Astronomy Research have announced a potentially groundbreaking study of more than 2,800 distant galaxies in search of signs of highly advanced “supercivilizations.” Unlike previous SETI efforts that scanned our local Milky Way galaxy for signs of advanced technology, called “technosignatures,” this latest effort leveraged the large viewing area and overall scanning power of the Murchison Widefield Array (MWA) in Western Australia to look at thousands of galaxies at once.

“This work represents a significant step forward in our efforts to detect signals from advanced extraterrestrial civilizations,” said Dr. Chenoa Tremblay of the SETI Institute and co-author of the study. “The MWA’s large field of view and low-frequency range make it an ideal tool for this type of study, and the boundaries we establish will guide future studies.”

Although no clear technosignatures were detected, the team says their study will set critical frequency and energy limits for future efforts to search the cosmos for signs of super-civilizations.

Hunting for Kardashev’s Super Civilizations

In a published study, the research team behind the unprecedented effort said they wanted to go beyond previous SETI studies by scanning multiple galaxies at once. But for the signal to be strong enough for us to detect it on Earth, it would have to be produced by a highly advanced civilization. The team said it would likely have to be produced by a Type II or Type III civilization on the Kardashev scale.

According to the study’s authors, “Type I civilizations (Kardashev) are able to access all the energy available on their planet, Type II civilizations can directly consume the energy of their star, and Type III civilizations are able to capture all the energy emitted by their galaxy.”

The researchers therefore explain that, in theory, civilizations at the upper end of the Kardashev scale “could produce large amounts of electromagnetic radiation detectable at galactic distances.” By comparison, humanity is considered a Type 0 civilization because we have not yet managed to capture all of the energy from our planet.

Scanning 2,800 galaxies at once

The SETI effort to locate technosignatures of super-civilizations began with a scan of the NASA/IPAC Extragalactic Database (NED). The team specifically searched for sources where the “pretype” was listed as “G” for galaxy. According to the study’s authors, “of the millions of objects cataloged within the 400-square-degree field of view (MWA), there were a total of 2,880 known galaxies from the full set of surveys available in NED.”

Once the region was selected, the scientists agreed to focus only on signals with a spectral resolution of 10 kHz, which could come from galaxies “within a 400-square-degree field of view” toward the supernova remnant called Vela. In addition, because the scientists were looking for signals that could be picked up from such incredibly large cosmic distances, they focused on low-frequency signals in the 98- to 128-MHz range.

The scanning of this region of space alone lasted 18 days and covered more than 2,800 galaxies, including 1,300 whose distance from Earth had been previously determined.

“Although MWA is less sensitive compared to single-antenna experiments, this work is important due to its unique frequency coverage, large instantaneous field of view (FOV), and point source resolution,” they write.

The scan did not detect any foreign signals.

After collecting more than 17 hours of usable data, the research team analyzed the data for low-frequency radio signals. According to the published study, they looked for signals that showed “a value of 6σ above local noise” using a standard astronomical noise estimator. That search yielded no results, with the team noting that “no such signals were detected at or above this level.”

However, scientists say their efforts have not been a complete failure.

“Although no signals were detected, we imposed strict limits on the transmitter power in 1,317 galaxies” whose distance from our Milky Way is already known. They explain that such limits will help refine future searches, including those looking for signs of advanced super-civilizations throughout the cosmos.

“Thanks to the sensitivity of modern radio telescopes, it will be possible to detect radiation coming from such a super-civilization even from galactic distances,” they write.

Next, the research team hopes to continue research in this area, as the search for technosignatures in this frequency space “will be crucial in the future.”

“The MWA continues to open up new ways to explore the Universe in search of intelligent civilisations and technosignatures, using the same data to study the astrophysics of stars and galaxies,” said study co-author Professor Steven Tingay from Curtin University. “This work is new and groundbreaking, but it also paves the way for future observations with even more powerful telescopes.”

Test “Extragalactic Widefield Technosignature Search Using Murchison Widefield Arrays” is published in Astrophysical Journal.

Christopher Plain is a science fiction and fantasy novelist and the lead science writer at The Debrief. Follow and connect with him on X, You can find more information about his books at plainfiction.com or email him directly at [email protected].