A new study unveiled at the Royal Astronomical Society’s 2025 National Astronomy Meeting in Durham, UK, explores how Earth’s electromagnetic emissions could be picked up by alien civilizations equipped with powerful radio telescopes — similar to cutting-edge instruments like the Green Bank Telescope in West Virginia.
Led by PhD researcher Ramiro Caisse Saide from the University of Manchester, the team focused on radar systems used at major international airports such as Heathrow, Gatwick, and New York’s JFK. These facilities generate a combined radio output of roughly 2 × 10¹⁵ watts — strong enough, the study suggests, to be detected from as far as 200 light-years away.
For comparison, Proxima Centauri b — the closest known potentially habitable exoplanet — lies just 4 light-years from Earth. Still, with current propulsion technology, reaching even that distance would take thousands of years.
Military radars, on the other hand, are more focused and directional — acting like powerful beacons sweeping across the sky. According to researchers, these systems can emit up to 1 × 10¹⁴ watts when they cross the field of view of a potential interstellar observer — a level of intensity that would clearly appear artificial to any technologically advanced civilization
“Depending on the observer’s location, these signals could appear up to a hundred times stronger,” explained Ramiro Caisse Saide.
Scientists believe that such unintentional emissions may qualify as technosignatures — detectable evidence of intelligent, technology-based life.
Beyond its relevance to the search for extraterrestrial life, the study also sheds light on how our technologies might be perceived from space. According to Professor Michael Garrett, a co-author of the research, understanding how our signals travel through the cosmos can help protect the radio spectrum, improve radar system design, and assess the impact of human technology on the space environment.
Ultimately, this investigation not only offers new tools to refine the search for alien civilizations but also invites us to reflect on how we are unintentionally making ourselves visible to the universe.
Although this study focuses on civilian and military radars installed at airports, it fits into a broader context of research examining how various human technologies emit signals that can be detected beyond Earth.
In a recently published work, scientists simulated how cell towers located in densely populated regions — such as China’s eastern coast — produce radio leakage that could potentially be picked up by alien radio telescopes from dozens of light-years away. The study estimated emissions on the order of 4 gigawatts, highlighting that even seemingly harmless systems from modern daily life could inadvertently act as “technological beacons” in the cosmos.
This type of emission — whether from airport radars, military systems, or telecommunications networks — contributes to a “technological signature” of humanity, the modern equivalent of footprints left in the sand. Scientists refer to this as technosignatures, and the study of these signals is becoming one of the central pillars of modern astrobiology.
