A recent study by Sofia Sheikh from the SETI Institute and her colleagues has reaffirmed that the interstellar object 3I/ATLAS is not of alien origin. This finding is the result of extensive observations conducted with the upgraded Allen Telescope Array (ATA) in July 2025, shortly after the object’s discovery.
The ATA, one of the world’s leading radio telescopes, dedicated 7.25 hours across five sessions to analyze 3I/ATLAS for potential artificial radio signals. Prior observations had already classified the comet as a natural celestial body, characterized by a coma, water outgassing, and a rapid rotational period of 16.8 hours. The purpose of ATA’s research was to determine if the object was emitting any synthetic signals.
With its recent upgrade featuring new “Antonio” cryogenic feeds, the ATA enhanced its capabilities significantly, providing improved signal reception in the frequency range of 1-12 GHz, which encompasses common communication signals like those in cellular and WiFi bands. This upgrade was supported by Franklin Antonio, founder of Qualcomm, whose contributions were instrumental in the array’s enhancements.
During the observational campaign, the ATA detected over 70 million potential signals. However, to sift through this data, a novel filtering method called the Breakthrough Listen Interesting Signal Search (bliss) algorithm was employed. This approach eliminated signals from known human electronic interference and focused solely on frequencies consistent with the expected movement of 3I/ATLAS. Following rigorous checks, they identified 211 candidate signals, but all were ultimately linked to Earth-based interference. This exhaustive process led to a conclusive “null” result, indicating no evidence of synthetic radio emissions from 3I/ATLAS.
The study also estimated the necessary power output for any potential signals to be detected, concluding that any civilization capable of dispatching such an interstellar object would likely utilize a radio transmitter of much higher power than that of everyday devices, such as cell phones.
Additionally, parallel investigations from other observatories, including the Green Bank Telescope in West Virginia, corroborated the ATA’s findings, ruling out any technological signatures and reinforcing the natural characteristics observed in 3I/ATLAS. Observations from MeerKAT in South Africa and the Vera C. Rubin Observatory in Chile further validated these conclusions.
As astronomers and scientists continue to monitor 3I/ATLAS as it travels through our solar system into deep space, further studies are anticipated. While the possibility of it being an artificial object has been conclusively dismissed, the interest surrounding this interstellar visitor remains high within the scientific community, ensuring ongoing research and exploration into its natural phenomena.