How your summer holiday could be 'helping' aliens detect Earth from 200 light-years away

As you check into the airport, browse duty-free, and count down the minutes to your holiday, consider this, aliens might be watching you.

According to new research presented at the Royal Astronomical Society's National Astronomy Meeting 2025, radar systems at major airports could be alerting intelligent alien civilisations to our presence.

Radar installations emit powerful electromagnetic signals that, according to research by the University of Manchester, could be detected by extraterrestrials up to 200 light-years away, if they have radio telescopes similar to those found here on Earth.

Lead author Ramiro Caisse Saide, a PhD student at the University of Manchester said, “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.”

  FREDERIC J. BROWN/AFP/Getty Images

The researchers simulated the way airport and military radar signals from New York’s JFK and London’s Heathrow and Gatwick propagate through space.

They then calculated the strength of Earth’s radio signature from the perspective of six nearby star systems:

• Barnard's Star (6 light-years distant)
• AU Microscopii (32 light-years)
• HD 48948 (55 light-years)
• HD 40307 (42 light-years)
• HD 216520 (64 light-years)
• LHS 475 (41 light-years)

Airport radar systems globally emit a combined radio output of 2×10¹⁵ watts, enough to be detectable from interstellar distances using telescopes akin to the Green Bank Telescope in West Virginia.

Military radar systems, which are more like a lighthouse beam sweeping the sky, generate bursts of radiation with peak emissions reaching 1×10¹⁴ watts.

By understanding how human-made signals appear from afar, scientists can search for similar signs from other star systems, refining how we might search for alien life.

Why not read…

• 'Alien' structure 'with stairs' discovered at the bottom of the sea
• Scientists have found 'evidence' of advanced alien civilisations

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