[Google AI Overview at the query, expanded ('AI Mode Conversation' is the expansion's header), signed out and incognito (operator defaults of 2026-10-01 and 2026-10-14). Received 2026-11-06 09:30 EST. The numbered citation links are Google redirects and are kept in the raw transcript; the source cards below the composition are listed in the cite list as pasted.]

[QUERENT] A Search for Radio Technosignatures from Interstellar Object 3I/ATLAS with the Allen Telescope Array

[SYSTEM] Astronomers using the SETI Institute's Allen Telescope Array searched the interstellar object 3I/ATLAS for artificial radio technosignatures and found no evidence of alien technology. [[1](https://www.google.com/goto?url=CAESXQHEIkXXBd8ThRSNUJnQqgtcmrH4N1c8ItRfTcc9lsEsv6XGiJ1BB5omHHcDS7bNQ-vKSBoW-3GGfxQfnwz5-hcZ5LTavmYTdcNcN9v7hDxyqT8J28JsZPX8C81R9w), [2](https://www.google.com/goto?url=CAESlwEBxCJF18BjEqwxHIz8yxbB7v9j5p3MmSDXgUt1I2vFs_aAhq8qYagf-u7jVrIOUFccS_jkedye0wAwWFvNowz82tlSjSPCxfxViycjNARKubbnGw-p5zUo05vKmYgaouN8T8KKRxhlsstStZV4yEwgq7hJcbVGUh-SD9eR3BReRFQwPAumKBXqhtpA6l7zlHYtR6CoBcKb), [3](https://www.google.com/goto?url=CAES2QEBxCJF16zbJusLLX-zAPD9KduvEHRC1-SwZsp7GABo5St5OcRcoSaCTa2eRLqOwrQpsxX3rK8VH6MGoHW3E91z4hcEWsFK93MM1R4MufrychsOonTRMtZKWQkexQalE9uYIGkvNlX0xqe9tcR7-54mTGK_MBvGJ0IY0aeI0gzjo3KNjGHhCe9HyRT56f9HgVb5Xh2te4xn8D4ujwVEHK1bJLQRk9K6eEkoVZzWhRvHiMIgOdpMYtXUPGyQiP0BUBceyTetKg_6q7k4VAgJG-bK_1-O8-QhiQ21)]
Key Details of the Study

* Observation Time: 7.25 hours of data collection across five sessions. [[1](https://www.google.com/goto?url=CAESpAEBxCJF1759D8KhE83izpcASAlIZi7E7Sne19eIvF8swEozT483uMYrjwHPipdZIOObtQ3ixerOjwtlryRJas6vmmfG8QVqYbwmXsVhF1vVGGwl_ArUAxF-h6pwo2QLHstSGflgq61lBNvR1Y9AfeLrNOXDoH5RJjVo6ZORupKcY8KSvlwXzC69d3sAbaLPQdM2j7lXDtTrLeqSAEXhoeu-629ufg), [2](https://www.google.com/goto?url=CAESXQHEIkXXBd8ThRSNUJnQqgtcmrH4N1c8ItRfTcc9lsEsv6XGiJ1BB5omHHcDS7bNQ-vKSBoW-3GGfxQfnwz5-hcZ5LTavmYTdcNcN9v7hDxyqT8J28JsZPX8C81R9w)]
* Frequency Range: 1 to 9 GHz. [[1](https://www.google.com/goto?url=CAESXQHEIkXXBd8ThRSNUJnQqgtcmrH4N1c8ItRfTcc9lsEsv6XGiJ1BB5omHHcDS7bNQ-vKSBoW-3GGfxQfnwz5-hcZ5LTavmYTdcNcN9v7hDxyqT8J28JsZPX8C81R9w)]
* Data Processing: The automated `bliss` pipeline detected ~74 million narrowband signals. After RFI (radio frequency interference) frequency and drift-rate blanking, this was reduced to ~2 million candidates, and further filtered down to 211 hits via `NBeamAnalysis` for visual inspection. [[1](https://www.google.com/goto?url=CAESXQHEIkXXBd8ThRSNUJnQqgtcmrH4N1c8ItRfTcc9lsEsv6XGiJ1BB5omHHcDS7bNQ-vKSBoW-3GGfxQfnwz5-hcZ5LTavmYTdcNcN9v7hDxyqT8J28JsZPX8C81R9w)]
* Results: Every single candidate signal was traced back to local human-made Earth technology, satellites, or interference—yielding zero artificial signals originating from the object. [[1](https://www.google.com/goto?url=CAES2QEBxCJF16zbJusLLX-zAPD9KduvEHRC1-SwZsp7GABo5St5OcRcoSaCTa2eRLqOwrQpsxX3rK8VH6MGoHW3E91z4hcEWsFK93MM1R4MufrychsOonTRMtZKWQkexQalE9uYIGkvNlX0xqe9tcR7-54mTGK_MBvGJ0IY0aeI0gzjo3KNjGHhCe9HyRT56f9HgVb5Xh2te4xn8D4ujwVEHK1bJLQRk9K6eEkoVZzWhRvHiMIgOdpMYtXUPGyQiP0BUBceyTetKg_6q7k4VAgJG-bK_1-O8-QhiQ21), [2](https://www.google.com/goto?url=CAESlwEBxCJF18BjEqwxHIz8yxbB7v9j5p3MmSDXgUt1I2vFs_aAhq8qYagf-u7jVrIOUFccS_jkedye0wAwWFvNowz82tlSjSPCxfxViycjNARKubbnGw-p5zUo05vKmYgaouN8T8KKRxhlsstStZV4yEwgq7hJcbVGUh-SD9eR3BReRFQwPAumKBXqhtpA6l7zlHYtR6CoBcKb)]
* Power Constraints: The non-detection rules out any active radio transmitters stronger than roughly 10 to 110 Watts on or near 3I/ATLAS. [[1](https://www.google.com/goto?url=CAESXQHEIkXXBd8ThRSNUJnQqgtcmrH4N1c8ItRfTcc9lsEsv6XGiJ1BB5omHHcDS7bNQ-vKSBoW-3GGfxQfnwz5-hcZ5LTavmYTdcNcN9v7hDxyqT8J28JsZPX8C81R9w), [2](https://www.google.com/goto?url=CAESlwEBxCJF18BjEqwxHIz8yxbB7v9j5p3MmSDXgUt1I2vFs_aAhq8qYagf-u7jVrIOUFccS_jkedye0wAwWFvNowz82tlSjSPCxfxViycjNARKubbnGw-p5zUo05vKmYgaouN8T8KKRxhlsstStZV4yEwgq7hJcbVGUh-SD9eR3BReRFQwPAumKBXqhtpA6l7zlHYtR6CoBcKb)]
* Conclusion: Alongside optical, infrared, and other global telescope campaigns (such as the Green Bank Telescope and MeerKAT), the data firmly reinforces that 3I/ATLAS is a natural comet. [[1](https://www.google.com/goto?url=CAESkgEBxCJF1-sYNrjlPg_MldJFQJK_kwBEQkYkdljO3TT3XGGPZ2nAWYyArrqejNjJlHRO04ZhusAJaKito1aCFnSWiHCPzT-b8Ljns7CYfEojGUByovQlLG0jH90sqJfvqUqcsKKAUj5hZ1LnltIa5ktrtkkx-JAtfxvkOjZ8tkchO4VaFwKu7EE5qhEY5g0aLZSOTQ), [2](https://www.google.com/goto?url=CAESXQHEIkXXx7hLVTrYwI5UCM7l4QxCJmcwWIgUOMwNMIrC8pWI3a51oSC5wR_I_GhTWPYtrMCvq8KT95_7iLlzlQciC8stiRDA1q6i2vPbmIkM1d2WoRoYHu7b60VJkg)]

You can read the full peer-reviewed study in [The Astronomical Journal via IOPscience](https://www.google.com/goto?url=CAESeAHEIkXXCftx_QOS5s5huwtFhcqByq93cqJbCPx375_6POFt1JG3fxS-h5rZDt1W-DeozNwEMIYiDNGtPgQCi6X836_ZMbNX_bzcZPmrTm0Y7VJQKGoadjve9hE6oS2lx7VcdOhzBRwFKqZtZS49a3lM3l2-BLp_UQ) or access the open-access draft on [arXiv](https://www.google.com/goto?url=CAESXQHEIkXXBd8ThRSNUJnQqgtcmrH4N1c8ItRfTcc9lsEsv6XGiJ1BB5omHHcDS7bNQ-vKSBoW-3GGfxQfnwz5-hcZ5LTavmYTdcNcN9v7hDxyqT8J28JsZPX8C81R9w). [[1](https://www.google.com/goto?url=CAESXQHEIkXXBd8ThRSNUJnQqgtcmrH4N1c8ItRfTcc9lsEsv6XGiJ1BB5omHHcDS7bNQ-vKSBoW-3GGfxQfnwz5-hcZ5LTavmYTdcNcN9v7hDxyqT8J28JsZPX8C81R9w), [2](https://www.google.com/goto?url=CAESeAHEIkXXCftx_QOS5s5huwtFhcqByq93cqJbCPx375_6POFt1JG3fxS-h5rZDt1W-DeozNwEMIYiDNGtPgQCi6X836_ZMbNX_bzcZPmrTm0Y7VJQKGoadjve9hE6oS2lx7VcdOhzBRwFKqZtZS49a3lM3l2-BLp_UQ)]
Would you like to know more about other telescopes that observed 3I/ATLAS (like the Green Bank Telescope) or the natural cometary characteristics discovered during its closest approach?
arXiv
[2512.18142] A Search for Radio Technosignatures from Interstellar Object 3I/ATLAS with the Allen Telescope Array
Observation: Radio technosignature search targeting interstellar object 3I/ATLAS using the Allen Telescope Array from 1-9 GHz during 7.25 hours of data collecti...
IOPscience
A Search for Radio Technosignatures from Interstellar Object 3I/ATLAS with the ...
Jun 3, 2026 — In this campaign, we used the SETI Institute's Allen Telescope Array to observe 3I/ATLAS from 1–9 GHz. We detected nearly 74 million narrowband ...
Phys.org
Interstellar object 3I/ATLAS reveals no technosignatures in seven-hour radio ...
Jun 3, 2026 — While no technosignatures were found, the study sets new constraints reinforcing that 3I/ATLAS is a natural object. The observations place upper ...
Berkeley SETI
Breakthrough Listen observations of interstellar object 3I/ATLAS
Discovery: Interstellar object 3I/ATLAS discovered July 1, 2025; behaves as natural object (hydroxyl signatures detected from water ice breakdown). Observations...
Universe Today
Inside the Massive Radio Search of Our Newest Interstellar Guest
Jan 6, 2026 — The ATA is one of the world's most powerful radio telescopes, and scanned interstellar comet 3I/ATLAS for a total of 7.25 hours over five ...
Sci.News
Astronomers Scan Interstellar Object 3I/ATLAS for Alien Radio Signals | Sci.News
Object: 3I/ATLAS (third confirmed interstellar object, discovered July 1, 2025 by ATLAS facility in Chile, perihelion October 29, 2025, exhibits natural cometar...
Space
Interstellar comet 3I/ATLAS is not an alien spacecraft: SETI hunt for 'technosignatures' comes up empty | Space
Object: Interstellar comet 3I/ATLAS (third confirmed interstellar object after 1I/'Oumuamua and 2I/Borisov; discovered July 1, 2025, by ATLAS project). Search: ...