Aliens may have detected Earth through airport radar

A new study from the University of Manchester suggests that the first experience an alien civilization might have of Earth is not through telecommunications or television. Instead, astronomers have shown that at a distance of up to 200 light years, the strongest source of radio emissions from Earth comes from airport radar systems, especially military radar.

Airport radars are capable of acting as beacons and could be detected by aliens from light years away. (Source: Shutterstock)

Airport radars scan the sky for aircraft, and in the process, they inadvertently leak large amounts of radio waves into space. With more than 40,000 airports worldwide, radar systems generate a total output of 2×10¹⁵ watts. If an alien civilization within 200 light years had a radio telescope comparable to the Green Bank Telescope in West Virginia, they could pick up the signal from the flight to Ibiza.

The difference lies in military radars. These devices are designed to be more directional and focused, creating distinctive emission patterns, like “cosmic lighthouses” scanning the sky. Although the peak emissions account for only 5% of the total radio emissions, their technical characteristics are clear enough for extraterrestrial observers to recognize them as artificial.

“It’s entirely possible that we could be emitting signals without even meaning to,” lead researcher Ramiro Caisse Saide, from the University of Manchester, told IFLScience. “Technology on Earth generates radio emissions, and what we want to know is whether a sufficiently advanced civilization could detect those traces.”

Aliens could be monitoring flights over our planet. (Source: Shutterstock)

Saide's team previously found that signals from cell towers can be picked up from 10 light years away. Airport radar can reach much farther.

The team simulated how radar signals would appear when viewed from several stars near Earth. The signal power would vary depending on where the radar is located on the planet's surface, and also depending on the viewing angle from the stars.

The nearest star to our Solar System is Proxima Centauri – about 4.2 light years away. While 200 light years may seem small compared to the size of the Milky Way (which is over 100,000 light years across), that region still contains more than 120,000 stars, opening up the possibility of intelligent life.

Proxima Centauri is only about 4.2 light years from Earth. (Source Space)

“The search for extraterrestrial intelligence is a field of scientific research that seeks to assess whether humanity is alone in the universe. We use technology as a measure of intelligence,” Saide added. “My research aims to clarify the question: If there were a civilization out there with similar capabilities in the radio field, would they be able to detect the radio traces produced by Earth?”

Minh Hoan

Source: https://vtcnews.vn/nguoi-ngoai-hanh-tinh-co-the-phat-hien-trai-dat-nho-radar-san-bay-ar953794.html