In a recent study, astronomers have confirmed that the interstellar object known as Comet 3I/ATLAS is a natural celestial body, not an alien spacecraft as some enthusiasts had speculated. Using the Green Bank Telescope in the Breakthrough Listen project, scientists conducted a thorough search for potential technosignatures—signals indicative of extraterrestrial technology—but found none.
3I/ATLAS, only the third interstellar object detected within our solar system after 1I/’Oumuamua in 2017 and 2I/Borisov in 2019, continues to captivate scientists and space fans alike. Despite initial hopes, the recent findings suggest it is a typical comet with no signs of artificial origin.
Lead researcher Benjamin Jacobson-Bell from the University of California, Berkeley, explained, “We all would have been thrilled to find technosignatures coming from 3I/ATLAS, but they’re just not there. Finding no signals was the expected outcome, given the evidence pointing to its natural cometary nature.”
The team utilized the Green Bank Telescope’s broad radio frequency range to search for narrowband radio signals—considered the most likely form of detectable extraterrestrial technosignatures due to their energy efficiency and long-distance travel. The sensitivity of the telescope allowed the team to detect signals as weak as 0.1 watts, significantly below the power of a typical cell phone, yet no such signals were identified.
While nine signals, termed “events,” were detected during the search, all were attributed to known human-made sources, such as terrestrial radio transmitters, and dismissed as false alarms.
Despite the lack of evidence for artificial signals, the findings reinforce that 3I/ATLAS behaves like a natural comet. However, Jacobson-Bell emphasizes the importance of continued exploration: “Interstellar objects are still highly intriguing. There’s a possibility that some could be intentional probes from other civilizations, so ongoing searches remain vital.”
He added that upcoming surveys, such as those conducted by the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST), are expected to increase the detection of interstellar objects. This will help scientists distinguish typical bodies from potential anomalies that might warrant further investigation into their origins.
While 3I/ATLAS appears to be a natural comet, researchers remain optimistic about future discoveries. “Public interest in interstellar objects is crucial,” Jacobson-Bell concluded. “One day, we might find one transmitting signals—until then, we have to keep looking.”