Scientists monitoring the interstellar visitor 3I/ATLAS have confirmed the detection of a series of narrow‑band radio pulses at 1 420 MHz – the frequency of the hydrogen line that has long been singled out in the search for extraterrestrial intelligence (SETI). The pulses, recorded by the Green Bank Telescope during a 12‑hour observing window in early October, appear to repeat in a sequence of durations that match the Fibonacci numbers 8 – 13 – 8 – 5 – 13 – 8 seconds. The pattern, shared widely on social media with the caption “Fibonacci signal from deep space,” has reignited speculation that the signal could be an intentional transmission from an intelligent source.
The observations were part of a coordinated campaign launched by NASA’s Deep Space Network and the European Space Agency (ESA) after 3I/ATLAS entered the inner Solar System and reached perihelion on 28 September. Dr. Priya Natarajan, an astrophysicist at the Institute for Advanced Study who is leading the SETI analysis, cautioned that “while the coincidence of the hydrogen line and a mathematically interesting sequence is intriguing, we must first exhaust all conventional explanations.” She noted that pulsars, rotating neutron stars, can emit quasi‑periodic bursts, and instrumental artifacts such as timing glitches in the backend electronics can masquerade as regular intervals.
To test these possibilities, the team is cross‑checking the Green Bank data with simultaneous recordings from the Parkes radio telescope in Australia and the MeerKAT array in South Africa. Preliminary results show that the pulse train is present in all three data streams, reducing the likelihood of a local hardware fault. However, Dr. Elena García of ESA’s Radio Astronomy Division emphasized that “natural astrophysical phenomena can produce seemingly ordered signals, especially when we look at them through the lens of human‑defined patterns.” She pointed to recent studies of fast radio bursts (FRBs) that exhibit sub‑pulse structures with quasi‑regular spacing, a phenomenon still under active investigation.
The timing of the detection has added fuel to the fire. The signal arrived within days of 3I/ATLAS’s closest approach to the Sun, a period when the object’s trajectory is best constrained and its interaction with solar radiation is strongest. Some members of the UAP (unidentified aerial phenomena) community have seized on the event, suggesting a link between the object’s perihelion passage and the emergence of “intelligent” signals. The scientific community, however, remains wary of conflating unrelated phenomena. “Correlation does not imply causation,” said Dr. Natarajan, referencing the long‑standing cautionary principle that guides SETI research.
The episode underscores the importance of open data sharing in the field. Both NASA and ESA have made the raw recordings publicly available through their respective archives, inviting independent analysts to scrutinize the signal. A petition submitted to the International Astronomical Union’s SETI Committee earlier this week calls for a formal verification protocol, similar to the one applied after the 1977 “Wow!” signal. Until a consensus emerges, researchers agree that the prudent course is to continue systematic observations of 3I/ATLAS and other interstellar interlopers, while keeping the public informed without resorting to sensational headlines.
