A new survey of more than 1,300 galaxies for extraterrestrial signals aims to help determine whether expectations of finding other civilizations beyond Earth are warranted.

In particular, as reported by LiveScience, the research was conducted by Chenoa Tremblay of the SETI Institute (Search for Extraterrestrial Intelligence) in California and Steven Tingay, director of the MWA (Murchison Widefield Array) from Curtin University in Australia.

The search was for low radio frequencies in the 80–300 MHz range. By comparison, SETI (which stands for Search for Extraterrestrial Intelligence) typically looks for alien signals at the hydrogen emission frequency of 1,420 MHz. The team focused on a 30-degree field of view in the constellation Vela, the Sails, which includes 2,880 galaxies.

Scientists Tremblay and Tingay focused on galaxies whose distances have been accurately calculated and which are 1,317 in number. Knowing the distances of the galaxies they were able to place limits on the power of any radio transmitters in them.

While their initial search failed to detect any extraterrestrial signal, Tremblay and Tingay concluded that they would be able to detect one with a transmitter power of 7 x 10^22 watts at a frequency of 100 MHz.

“This research represents an important step forward in our efforts to detect signals from extraterrestrial civilizations”Tremblay said. “MWA’s large field of view and low-frequency range make it an ideal tool for this kind of research, and the limits we set will guide future studies.”.

So far no sign of extraterrestrial life has been found but scientists claim there are as many as 2 trillion galaxies in the observable universewhile we have searched for only a small fraction of them, and only for a short period of time. Just because alien life hasn’t been detected so far doesn’t necessarily mean it doesn’t exist, they point out. “It’s just that our observations aren’t complete enough to say anything about its existence. We’re just not sure.”

Previous failed attempts to find other cultures

In 2015, for example, Glimping Heat from Alien Technologies (G-HAT) examined 100,000 galaxies with NASA’s Wide Field Infrared Survey Telescope (WISE) in search of civilizations that may have created “Dyson clusters” around all stars. None were found in the corresponding galaxies. In 2023, a team led by Yuri Uno of Chung Hsing National University in Taiwan suggested that there could be no more than one civilization within three billion light-years of us that exhibits a radio transmitter with a power greater than 7.7 x 10 ^26 watts in the Galaxy.

That same year, Michael Garrett of the Jodrell Bank Center for Astrophysics and Breakthrough Listen’s Andrew Siemion conducted a survey of background galaxies to narrow down the maximum detectable power, arriving at a range of about 10^23 watts to 10^26 watts. (The exact peak strength for a possible signal will depend on the distance from the galaxy it originates from.) Finally, Carmen Choza of the SETI Institute led a team that recently conducted a targeted survey of 97 galaxies with the Green Bank Telescope, but did not detected nothing.