Your Local Airport Might Be Attracting Alien Attention

RiverSci/Tech2025-07-228690

Here’s what you’ll learn when you read this story:

The SETI Institute’s goal is to lead a science-based mission to find evidence of intelligent life beyond our own planet.

A new study shows what aliens within 200 light-years might see if they trained their own powerful radio telescopes on our planet.

It turns out the aviation radar—both civilian and military—would create a repeatable Effective Isotropic Radiated Power (EIRP) pattern due to the distribution of radar equipment across the Earth’s surface.

Professional outfits like the Search for Extraterrestrial Intelligence (SETI) Institute scan the skies with radio telescopes for any sign of extraterrestrial life. They’re especially tuned in to potential presence of technosignatures—electromagnetic radiation emitted by an advanced society’s technology. While that effort has produced some exciting close calls, humanity most likely has yet to find any sign of alien life.

Of course, there’s another way to look at this problem. If an alien civilization in our galactic neighbor also had their own SETI-esque programs—similarly probing the skies in search for an answer to that ever-elusive “Are we alone?” question—could they hear us?

Well, as it turns out, the answer is an emphatic “yes”—not, however, because we’re purposefully shooting some kind of high-powered radio beam into the cosmos that’s acting like a galactic flare gun. No, aliens could hear us just from our everyday airport and military radar systems.

In a new study—the preliminary results of which were revealed at the Royal Astronomical Society's National Astronomy Meeting 2025 in Durham, U.K.—lead researcher Ramiro Caisse Saide from the University of Manchester concluded that an alien civilization within 200 light-years of Earth could likely spot our planet’s radar signals using an advanced radio telescope similar to the Green Bank Telescope in West Virginia. The study concluded that worldwide airport radar alone outputs a radio signal of roughly 2×10¹⁵ watts, while military radar outputs distinctive directional radio beams up to 1×10¹⁴ watts.

At first, 200 light-years may not seem like a lot—after all, the Milky Way stretches some 100,000 light-years across. But even a distance this short (at cosmic scales, at least) includes some 120,000 stars, which very likely host plenty of candidates capable of sustaining life.

“This would look clearly artificial to anyone watching from interstellar distances with powerful radio telescopes,” Caisse Saide said in a press statement. “In fact, these military signals can appear up to a hundred times stronger from certain points in space, depending on where an observer is located.”

The authors looked at this “hidden electromagnetic leakage” from the perspective of six stellar systems: Barnard star (6 light-years away), HD 48948 (55 light-years away), HD 40307 (42 light-years away), HD 216520 (64 light-years away), LHS 475 (40 light-years away), and AU Microscopii (32 light-years away).

To help others understand what the ‘leakage’ might look like, the researchers published a video showing the mean distribution of Earth’s Effective Isotropic Radiated Power (EIRP) over a 24-hour period as it would appear on AU Microscopii. A distinct pattern emerges based on the distribution of radio equipment across the planet. So, if some alien civilization took a keen interest in a particular rocky planet located in the Origin-Cygnus arm of the galaxy, this clearly artificial EIRP signature might just raise an eyebrow (or whatever aliens would do to show confusion).

“Our findings suggest that radar signals—produced unintentionally by any planet with advanced technology and complex aviation system—could act as a universal sign of intelligent life,” Caisse Saide said in a press statement. “In this way, our work supports both the scientific quest to answer the question ‘Are we alone?’ and practical efforts to manage the influence of technology on our world and beyond.”