By Margherita Bassi Published February 9, 2025 | Comments (0) | How might a twin Earth with human-like life and technology detect our planet? Zayna Sheikh Having yet to discover any evidence of extraterrestrial life, its difficult to theorize about the kinds of beings that might exist beyond the reaches of our telescopes. Could there be an Earth-like planet with human-like beings and technology searching for us as ardently as were searching for them? Although a planet with life and technology similar to ours may be rare, studying how such beings might detect Earth could help advance our own search for intelligent life. As such, a team of researchers led by the Search for Extraterrestrial Intelligence (SETI) Institutes Sofia Sheikh analyzed how a twin Earth might detect evidence of humanity on our planet, given our own standard of modern technology. Their theoretical study was published Monday in The Astronomical Journal. One of the most satisfying aspects of this work was getting to use SETI as a cosmic mirror. What does Earth look like to the rest of the galaxy? And how would our current impacts on our planet be perceived? Sheikh said in a SETI Institute statement. While of course, we cannot know the answer, this work allowed us to extrapolate and imagine what we might assume if we ever discover a planet, with, say, high concentrations of pollutants in its atmosphere. Sheikh and her team studied Earths technosignatures: potential signs of intelligent life with advanced technology, such as radio signals, artificial light, and/or nitrogen dioxide emissions. Indeed, our current or shortly forthcoming instruments, including the Habitable Worlds Observatory (HWO), have the potential to detect nitrogen dioxide emissions up to 5.7 light-years away, which is farther than Earths closest star after the Sun. However, the researchers revealed that powerful radio signals such as those formerly emitted by the now-collapsed Arecibo Observatoryare Earths most perceptible technosignaturepotentially detectable up to 12,000 light-years away. The furthest distances from which Earths technosignatures could be detected using technology similar to our own, as well as some astronomical objects. SETI Institute Our goal with this project was to bring SETI back down to Earth for a moment and think about where we really are today with Earths technosignatures and detection capabilities, said Macy Huston of the University of California, Berkeley, a co-author of the study. In SETI, we should never assume other life and technology would be just like ours, but quantifying what ours means can help put SETI searches into perspective.In a hypothetical scenario, the closer an alien civilization is to Earth, the more technosignatures it would detectoften picking up multiple signals at once. In addition to radio signals and nitrogen dioxide emissions, they would eventually note other human-made signatures such as satellites, lasers, heat islands, and city lights. We have a multiwavelength constellation of technosignatures, with more of the constellation becoming visible the closer the observer becomes, the researchers wrote in the study. Sheikhs team claims to be the first to have studied technosignatures collectively rather than individually.While they admit that there probably isnt an Earth twin out there, analyzing our own technosignatures can nevertheless inform how we understand evidence of life and, as a consequence, how we search for it beyond our planet.Daily NewsletterYou May Also Like By Margherita Bassi Published February 6, 2025 By Isaac Schultz Published February 4, 2025 By Margherita Bassi Published February 1, 2025 By Isaac Schultz Published January 29, 2025 By Margherita Bassi Published January 23, 2025 By Passant Rabie Published January 21, 2025