And the 3I/ATLAS went about its business. Unfortunately, there are no signs that it is an extraterrestrial spacecraft.

Radio observations collected the day before the object’s closest approach to Earth find no evidence of technosignatures from the third known interstellar visitor.

Since the interstellar object was discovered on July 1, 2025, it has attracted great attention, fueling speculation, hopes and fears that it could contain signs of civilizations technologically advanced technologies outside our solar system.

With great sadness for all those who hoped that we were finally facing the first contact with an extraterrestrial civilization, with the astronomer, the comet passed the closest point to Earth on the 19th — and went about its business, in the style of .

In a new report, recently pre-published on arXiv, a team of researchers detailed the conclusions from radio observations carried out with the Green Bank radio telescope, as part of the program, created to search for signs of extraterrestrial life.

According to the authors of the article, the radio observations, collected on December 18, 2025, the day before the object’s closest approach to Earth, find no evidence of technosignatures coming from 3I/ATLAS.

Natural astrophysical object or alien spacecraft?

Only two other ISOs have ever been observed entering our solar system. The first, , was initially classified as an asteroid, then as a comet; The second, , was considered a comet, recalls .

3I/ATLAS presents all typical comet characteristics. “It looks like a comet. Does comet things. It very, very strongly resembles, in practically every way, the comets we know. It’s a comet“, had already concluded Tom StatlerNASA’s chief scientist for small bodies in the solar system.

Still, these objects tend to give rise to speculation when they are discovered. After the discovery of 3I/ATLAS, many rumors circulated online about supposed unusual characteristics that would indicate alien technology.

“There is, at this time, no evidence that suggests that the interstellar objects we know about be something else other than natural astrophysical objects”, say the authors of the new work.

“However, taking into account the small number of objects of this type known, only three to date, and the plausibility of interstellar probes as technosignatures, an in-depth study is warranted”, highlight the researchers.

Six months after its discovery, several telescopes have already collected data in different bands of the spectrum — radio, infrared, X-rays and optical — and this data has been analyzed by several researchers. According to SETI, none of these observations revealed signs of technosignatures.

Observations at Green Bank

The researchers involved in the new study say that interstellar probes, if they exist, would probably communicate through radio signals narrowband, due to its transmission efficiency and low attenuation of these signals in interstellar space.

Therefore, the team searched for signs andm four band radio different, between 1 and 12 GHz, precisely at the time of the comet’s closest approach.

The research initially detected more than 471 thousand candidate signalsbut, after applying a celestial location filter, what remained just nine “events”.

A more detailed analysis revealed that these were the result of radio interference, as they also appeared in off-target scans or were already known as contaminants.

Even with higher sensitivity levels, the analysis did not find any candidate signals for technosignatures from 3I/ATLAS, in line with the results of other studies.

“Our analysis concluded that there are no isotropic transmitters continuous wave above 0.1W at the 3I/ATLAS location. For comparison, a cell phone is an isotropic continuous wave transmitter with around 1W”, conclude the study authors.

Therefore, we are all still waiting for the…”first contact“.