What Happened When 3I/Atlas Was Scanned For Aliens? - Results Are Finally Here

Breakthrough Listen's radio scan of 3I/ATLAS reveals the truth behind the alien speculation

All the months of conspiracy with 3I/Atlas, and whether it is an alien spaceship, might have finally got an answer. When the mysterious interstellar visitor 3I/ATLAS entered our solar system in July 2025, it got global attention like never before.

Yes, it is only the third confirmed object known to have come from beyond our star's neighbourhood. 3I/ATLAS gave scientists and the public, as well, a rare and unmissable chance to study a foreign cosmic wanderer close to Earth.

Almost from the moment it was discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Chile, theories went insane online about its true nature. Some people said it might be more than a comet, even going so far as to say that it could be an alien probe. Those ideas are still viral across social media and science blogs, leading to multiple debates about what clues this distant visitor might hold about life elsewhere in the universe.

How 3I/ATLAS Became the Focus of Alien Controversy

Now, interest in 3I/ATLAS was not purely academic. Like its predecessors 1I/'Oumuamua and 2I/Borisov, its interstellar origin made it unusual, but early looks into it saw features that seemed strange to some people.

Then, researchers soon documented that the object sported a coma of gas and dust as it warmed near the Sun, which is a characteristic most commonly associated with comets. But this alone did not dampen the conspiracy about aliens. Many people pointed to the object's trajectory, the alignment of its tail, and observations of shifting jets and anti tails as potential anomalies, saying they could mean something artificial.

Moreover, big voices in these discussions included astrophysicist Avi Loeb, who attracted further attention by commenting that certain properties might hint at an engineered origin instead of a standard comet. Others added to this by theories of unusual chemical emissions and unexpected changes in appearance, and this added fertile ground for all that alien conspiracy.

Furthermore, this conspiracy was taken to the next level through social platforms, where overhyped interpretations of observations took hold. In some corners of Reddit and Twitter, especially, people said that jets behaved like propulsion systems or that tail structures defied natural physics. Comments even floated the idea that the object could be a controlled probe or extraterrestrial artefact.

Fact Check: What Science Actually Found

Time to get down to the ET test that took place. After all the conspiracies, astronomers and focused research projects pursued systematic and exhaustive observations of 3I/ATLAS. The most important of these was a concentrated search for technosignatures, which are signs of technology such as artificial radio transmissions led by the Breakthrough Listen project.

Then, on 18 December 2025, the programme trained the 100-metre Robert C. Byrd Green Bank Telescope in the United States on 3I/ATLAS as it made its closest approach to Earth. Furthermore, a bunch of radio frequencies between 1 and 12 gigahertz, which are considered prime territory for potential interstellar communications, were sent out as the telescope scanned for narrowband signals that could prove an artificial origin like that of aliens. This indeed was the most sensitive and comprehensive search for alien technosignatures ever attempted on an interstellar visitor.

The results of the radio search were clear. Although more than 471,000 raw candidate signals were initially detected, careful filtering to remove radio interference from satellites, aircraft and Earth-based sources reduced this to just a handful of patterns. Then, further analysis confirmed that every remaining candidate was attributable to known noise or off target interference.

Importantly, no strong artificial radio transmissions were found at a strength exceeding about 0.1 watts. Practically, that means even low power emitters like basic walkie-talkies or devices weaker than a mobile phone would have been picked up if they were broadcasting from the object's location. No such emissions were detected.

Also, beyond the radio search, a whole lot of observations from space and ground based telescopes continued to paint a picture of a natural comet. NASA imagery from the Hubble Space Telescope and missions such as Perseverance's Mastcam-Z showed an object with a diffuse coma and tail structures consistent with dust and gas ejected by solar heating.

Infrared studies by the James Webb Space Telescope also added further detail about the composition of the coma, revealing a mix of carbon dioxide and other volatiles similar to what one might expect from cometary bodies. Other studies detected hydroxyl signatures associated with water activity, reinforcing the interpretation that 3I/ATLAS behaves like a comet and not a craft of extraterrestrial origin. So as of now, 3I/Atlas has no aliens.