Rare Interstellar Object 3I/ATLAS Fails Alien Test, Scientists Say

The interstellar visitor 3I/ATLAS has piqued widespread interest since it was spotted entering our solar system on July 1, 2025, and led to speculation online about whether or not it could be alien technology. These ideas have gained traction since only two such objects have been observed to enter the solar system. To challenge these assertions, researchers conducted the most sensitive radio observations ever with the Green Bank Telescope. The new results reveal no signs of 3I/ATLAS transmitting signals associated with advanced civilisations, pointing instead to a natural cosmic origin.

Breakthrough Listen Observations Find 3I/ATLAS Shows Natural, Comet-Like Signals

According to a study posted on the arXiv preprint server, the observations were made on December 18, 2025, as part of the Breakthrough Listen programme, just one day before the object's closest approach to Earth. The researchers scanned radio frequencies between 1 and 12 gigahertz, a range commonly considered efficient for interstellar communication, and analysed the data for any artificial patterns.

3I/ATLAS becomes the third interstellar visitor discovered, after 1I/‘Oumuamua and 2I/Borisov. Although early rumours centred on unexplained characteristics, astronomers claim that this object exhibits typical comet features like a coma and a compact, non-elongated nucleus. Similar speculation had surrounded earlier interstellar objects before natural explanations became clear.

Radio Scan of 3I/ATLAS Rules Out Artificial Signals, Favors Natural Origin

The radio search initially detected more than 471,000 possible signals. After filtering out background noise and Earth-based interference, only nine events remained, all of which were traced to known radio contamination. The researchers noted that no continuous artificial transmitter stronger than 0.1 watts was detected at the object's location.

Scientists report multiwavelength studies of 3I/ATLAS show no technosignatures yet; ongoing observations, including space telescopes, strongly support a natural origin.