Alien-signal hunt finds nothing from interstellar comet 3I/ATLAS after Green Bank scan
A search for possible technosignatures — potential signs of advanced technology — in the interstellar comet 3I/ATLAS found no credible radio transmissions, Breakthrough Listen researchers reported. The team said its campaign detected no candidate signals down to the 100 milliwatt level. arXiv The finding matters because 3I/ATLAS is a rare visitor from outside the solar system, and scientists had a limited window to scrutinize it as it swept past Earth. NASA says the comet posed no threat and came no closer than about 270 million km, after being reported to the Minor Planet Center on July 1, 2025 by the NASA-funded ATLAS survey in Chile.