A recent study by researchers at the University of Manchester explored Earth’s radar systems as a potential technological signature detectable by extraterrestrial observers. While SETI typically emphasizes intentional transmissions, this study focused on the unintended electromagnetic emissions from civilian and military radar systems at airports. These technologies constitute vital components of advanced civilizations and produce radio emissions that can be identified across interstellar distances. The authors investigated how the global distribution of radar installations influences the temporal characteristics of Earth’s radio signatures as viewed from six specific star systems: Bernard Star, HD 40307, AU Microscope, HD 216520, and LHS 475. The results indicate that radar systems represent one of the most detectable and unintended technological signatures of advanced civilizations, paving the way for the possible detection of extraterrestrial intelligence.
Ramiro Saide et al. examined how extraterrestrial leaks are concealed from Earth up to 200 light-years away if they possessed a radio telescope similar to ours. Image credit: Gemini AI.
“Our investigation revealed that the airport radar systems, which manage air traffic, emit a staggering total of 2×1015 radio signals,” stated Ramilo Kais Said, a student at the University of Manchester.
“To provide context, the nearest potentially habitable exoplanet beyond our solar system is Proxima Centauri B, located four light-years away.”
“These signals will continue to reach spacecraft utilizing current technology for thousands of years.”
Military radar systems, which are more focused and directional, create unique emissions akin to lighthouse beams that illuminate specific fields of view.14
“To observers at interstellar distances with advanced radio telescopes, these emissions would obviously appear artificial,” remarked Kaisse Saide.
“Indeed, these military signals can appear up to 100 times more intense from a particular vantage point in the universe, contingent on the observer’s location.”
“Our findings indicate that radar signals unintentionally produced by any technologically advanced civilization with complex aviation systems could serve as a universal sign of intelligent life.”
This research not only guides the search for extraterrestrial civilizations by pinpointing promising technological signatures but also enhances our understanding of how human technology is perceived from space.
“Insights into how our signals propagate through space offer valuable lessons on safeguarding our radio spectrum for communication and designing future radar systems,” stated Professor Michael Garrett from the University of Manchester.
“The methods we developed for modeling and detecting these faint signals hold promise for applications in astronomy, planetary defense, and assessing the impacts of human technology on the space environment.”
“Thus, our work contributes to scientific endeavors addressing the question, ‘Are we alone?'” Kaisse Saide noted.
The researchers presented their results today at the National Astronomical Conference of the Royal Astronomical Society 2025 in Durham, England.
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Ramiro Saide et al. investigate airport civilian and military radar emissions as detectable markers for extraterrestrial civilizations. NAM 2025
Source: www.sci.news
