SETI Uses Radio Frequencies to Look for Alien Life in More Than 1,000 Galaxies

Search for Extraterrestrial Intelligence (SETI) recently conducted a search of more than 1,300 galaxies for signs of alien life using unexplored low radio frequencies. The search was reportedly performed using the Murchison Widefield Array (MWA), a radio telescope located in the Australian outback. This effort targeted radio frequencies in the 80–300MHz range, a relatively uncharted area for SETI, which traditionally focuses on higher frequencies like the 1,420 MHz hydrogen emission line. Despite the search, no extraterrestrial signals were detected, though the findings have helped to refine the expectations of possible alien transmitter power.

Exploring Uncharted Frequencies

The search was led by Chenoa Tremblay from the SETI Institute in California and Steven Tingay, the director of the MWA at Curtin University in Australia. Their work focused on a 30-degree field of view in the Vela constellation, examining 2,880 galaxies. 

Among these, the distances to 1,317 galaxies were known with high accuracy, allowing the researchers to place constraints on the power of any potential transmitters in those galaxies. The results indicated that the search might have detected a signal with a transmitter power of 7 x 10^22 watts at 100 MHz.

Significance of the Findings

Although no signals were found, the study has provided valuable insights for future SETI research. The constraints set by this search will guide further studies, particularly in the low-frequency range. Tremblay and Tingay noted that Earth itself has powerful low-frequency radio emitters, which justifies the continued exploration of this range, according to a Live Science report. The research highlights the importance of covering a wide range of frequencies to increase the chances of detecting extraterrestrial signals in the future.

As the search for alien life continues, these findings underscore the challenges and complexities involved in scanning the cosmos for signs of intelligent civilizations.