NEW YORK, January 4, 2026, 05:41 ET
- Breakthrough Listen used the Green Bank Telescope to search 3I/ATLAS for artificial radio signals and reported no detections.
- The null result adds to the case that 3I/ATLAS is a natural interstellar comet, despite lingering online speculation.
- Harvard astronomer Avi Loeb has pointed to unusual jet patterns in Hubble images as worth closer scrutiny.
Scientists hunting for signs of alien technology from interstellar comet 3I/ATLAS reported no radio signals that could be traced to the object, after aiming one of the world’s most sensitive dishes at it during its recent close pass by Earth.
The result matters because 3I/ATLAS is rare — only the third known object confirmed to have come from outside the solar system — and it is already heading back out, shrinking the window for close-up observations.
It also lands as public fascination around the comet has surged, fueled by claims that unusual behavior might hint at technology rather than ice and dust.
In a preprint posted on arXiv, astronomer Ben Jacobson-Bell and co-authors described a Green Bank Telescope search across 1–12 GHz and wrote: “We report a nondetection of candidate signals down to the 100 mW level.” arXiv
Harvard astronomer Avi Loeb has argued that recent Hubble images show a puzzling geometry: a sun-facing “anti-tail” and three smaller jets separated by about 120 degrees, with a changing orientation that he linked to the nucleus’ rotation. He estimated the odds of one key alignment arising by chance at 0.2% and said it deserves debate. Medium
NASA has publicly rejected claims that 3I/ATLAS is an alien spacecraft, saying it looks and behaves like a comet, with a coma — the hazy cloud of gas and dust around its nucleus — and a tail of dust. Agency officials have said it poses no threat to Earth.
The Breakthrough Listen observations were carried out just before the comet’s closest approach, using the 100-meter Robert C. Byrd Green Bank Telescope in West Virginia, researchers and science outlets reported.
Signals did appear in the data at first, but teams narrowed them down by comparing on-target scans with off-target pointing, and the remaining candidates were ultimately identified as human-made radio interference, according to reports on the analysis.
The search focused on “technosignatures,” a catch-all term for potential signs of technology — in this case, narrowband radio transmissions that might stand out from natural astrophysical emissions.
The lack of a detection does not end scientific interest in 3I/ATLAS, researchers have argued, because the sample size for interstellar visitors remains tiny and the objects offer clues to how other planetary systems form and evolve.
Outside the lab work, the comet has also become a proxy debate about readiness. In a Times of Israel blog post, commentator Rafi Glick called 3I/ATLAS a “wake-up call,” urging a more coordinated global approach to studying future interstellar objects and arguing that new survey capabilities could make such encounters more frequent. Timesofisrael
