Summary
Space.com (Mike Wall) reports on a new Astronomical Journal study (published June 3, 2026) in which a SETI Institute-led team searched 3i-atlas for radio technosignatures and found none — a result the authors frame as scientifically valuable rather than disappointing. Lead author sofia-sheikh and co-author Valeria Garcia Lopez (Furman University) used the SETI Institute’s Allen Telescope Array at the Hat Creek Radio Observatory shortly after the comet’s July 1, 2025 discovery, collecting more than seven hours of observations looking for narrowband radio emissions. The team flagged nearly 74 million candidate signals, culled them to about 200 after removing human interference and motion artifacts, and ultimately explained all of them as terrestrial or satellite emissions. The observations place upper limits on any transmitter on or near 3I/ATLAS, ruling out signals stronger than roughly 10–110 watts (about a household appliance). The study reinforces that 3I/ATLAS is a natural object, consistent with the earlier FAST narrowband search and counter to avi-loeb’s speculative “Trojan Horse” framing.
Key Claims
- No radio technosignature detected from 3I/ATLAS over 7+ hours of Allen Telescope Array observations (Sheikh et al., Astronomical Journal)
- ~74 million narrowband candidate signals reduced to ~200, all attributable to Earth-based sources or orbiting satellites (Sheikh et al.)
- Observations rule out any radio transmitter stronger than ~10–110 W on or near 3I/ATLAS over the detected frequencies (SETI Institute)
- Result “sets new constraints reinforcing that 3I/ATLAS is a natural object” (SETI Institute)
- Telescope observations strongly suggest all three known interstellar objects (1I/ʻOumuamua, 2I/Borisov, 3I/ATLAS) are natural comets ejected from other solar systems (per source)
- Motivation framed via Voyager: humanity’s own probes will one day be extraterrestrial artifacts, so understanding the natural baseline helps flag future anomalies (Sheikh)
Notable Quotes
“The results from 3I/ATLAS show how realistic it is to detect a signal with the technology we have today… it is important to keep searching for technosignatures, even from objects we might not expect to have signals.” — Valeria Garcia Lopez, Furman University
“Eventually, our own Voyager spacecraft will be extraterrestrial artifacts in other stellar systems. Given that, it is important that we understand the natural distribution of interstellar objects so that we will be able to identify any anomalies that could one day be signs of an artificial interstellar object.” — Sofia Sheikh
“The observations place upper limits on the power of any radio transmitter on or near 3I/ATLAS, ruling out signals stronger than about 10-110 watts, approximately the power of a household appliance.” — SETI Institute