Scientists with the SETI Institute have accomplished a seek for possible technological signals coming from 3I/ATLAS, the third known interstellar object to go through our Solar System. Using the Allen Telescope Array (ATA) at Northern California’s Hat Creek Radio Observatory, researchers examined a broad range of radio frequencies for evidence of extraterrestrial technology. As expected based on previous observations, they found no signs of artificial signals, further supporting the conclusion that 3I/ATLAS is a natural comet-like object.
First identified in July 2025, 3I/ATLAS is just the third confirmed interstellar object ever observed entering our Solar System. It follows the discoveries of 1I/’Oumuamua and 2I/Borisov, each of which originated outside our planetary neighborhood.
Since it formed around one other star, 3I/ATLAS offers scientists a helpful likelihood to review material from a distinct stellar system and gain insights into how planets and planetary systems develop. Although current evidence strongly points to a natural origin, researchers also view interstellar visitors as necessary targets within the seek for technosignatures. Within the unlikely event that considered one of these objects were artificial, it could reveal detectable technology and potentially provide the primary evidence of life beyond Earth.
“Eventually, our own Voyager spacecraft will likely be extraterrestrial artifacts in other stellar systems,” said Dr. Sofia Sheikh, lead writer on the paper. “On condition that, it will be important that we understand the natural distribution of interstellar objects so that we’ll give you the chance to discover any anomalies that might someday be signs of a synthetic interstellar object.”
To research that possibility, the team observed 3I/ATLAS for greater than seven hours using the ATA. The observations covered frequencies from 1 to 9 gigahertz, a variety suitable for detecting narrowband radio transmissions. Such signals are usually not known to occur naturally and can be considered evidence of technology.
Sorting Through Tens of millions of Signals
Through the search, researchers detected nearly 74 million narrowband signals. Most were quickly identified as human-made interference.
After removing signals linked to Earth-based technology and narrowing the search to signals that matched the item’s motion, only about 200 candidates remained. Further evaluation showed that each considered one of those signals originated from technology on Earth or from satellites orbiting our planet.
No Technosignatures Detected
The search uncovered no evidence of extraterrestrial technology. Nevertheless, the outcomes provide additional support for the conclusion that 3I/ATLAS is a natural object.
The observations also established latest limits on the strength of any possible radio transmitter positioned on or near 3I/ATLAS. Across the frequencies examined, the study ruled out transmissions stronger than roughly 10-110 watts, comparable to the ability consumption of a typical household appliance.
“The outcomes from 3I/ATLAS show how realistic it’s to detect a signal with the technology now we have today,” said Valeria Garcia Lopez, co-author. “That’s the reason it will be important to maintain trying to find technosignatures, even from objects we may not expect to have signals.”
Rapid Response to Recent Interstellar Discoveries
The study highlights the Allen Telescope Array’s ability to reply quickly when unusual objects are discovered. Observations of 3I/ATLAS began lower than 24 hours after the announcement of its discovery, demonstrating how rapidly the system might be deployed.
Beyond the seek for intelligent life, observations of interstellar visitors help scientists higher understand the physical characteristics of those objects as they travel through the Solar System.
As astronomers proceed finding latest interstellar objects, every one provides one other opportunity to look for technosignatures while expanding our knowledge of each natural and potentially technological phenomena beyond our Solar System.