After 74 million hits, SETI finds no sign that 3I/ATLAS is an alien probe

In July 2025, astronomers detected a mysterious object entering the solar system from interstellar space. Since then, the discovery has sparked widespread interest, fueling debate over its origins and prompting speculation about its potential extraterrestrial connections.

However, despite the theories, a fresh radio search has turned up no sign that the object, now named 3I/ATLAS, is emitting anything artificial, despite months of claims that the interstellar body might be alien technology.

What happened?

According to Futurism, astronomers first identified 3I/ATLAS in July 2025 after detecting it moving through the solar system on an interstellar path, and the discovery quickly fueled heavy online speculation.

Harvard astronomer Avi Loeb was among those arguing that the object's odd characteristics could fit an ancient extraterrestrial artifact rather than a normal comet.

To check that possibility directly, scientists from Berkeley University's Search for Intelligent Life Institute and alien-hunting astronomy project Breakthrough Listen scanned a range of radio frequencies to see if the object was emitting any artificial signatures, as Futurism reported.

The team's new paper, published in The Astronomical Journal, relied on the Allen Telescope Array near San Francisco. 

According to the paper, the observations initially produced "nearly 74 million narrowband hits in 7.25 hours of data." Once the team removed radio-frequency interference from human sources, including communications equipment, the pool fell to roughly two million candidates.

From there, an algorithm reduced the remaining set to 211 signals worth a follow-up. None survived further review, and the paper said all were "easily attributable to RFI." Earlier work with the Green Bank Telescope likewise found no "candidate signals."

Why does it matter?

Although the 3I/ATLAS was likely not an alien probe, the search also showed that scientists now have a practical way to investigate strange objects with modern technology.

When an unusual visitor appears, researchers can use existing telescopes and advanced filtering methods to separate genuine anomalies from the electronic noise created here on Earth.

Interstellar objects offer rare opportunities to study material from beyond our solar system. Each can provide clues about how planetary systems form, what kinds of debris travel between stars, and offer unknown information about our universe. 

What are people saying?

Researchers said the null result was still a success.

Co-author Valeria Garcia Lopez said, "The results from 3I/ATLAS show how realistic it is to detect a signal with the technology we have today. That is why it is important to keep searching for technosignatures, even from objects we might not expect to have signals."

Lead author Sofia Sheikh placed the findings in a wider context.

"Eventually, our own Voyager spacecraft will be extraterrestrial artifacts in other stellar systems," Sheikh said. "Given that, it is important that we understand the natural distribution of interstellar objects so that we will be able to identify any anomalies that could one day be signs of an artificial interstellar object."

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