---
title: "Aliens Didn't Call: SETI Scanned Comet 3I/ATLAS and Found Only Terrestrial Interference"
description: "The SETI Institute has completed its scan of the interstellar comet 3I/ATLAS for alien signals. Despite detecting 74 million pulses, all were found to be terrestrial interference from satellites and equipment. However, the experiment proved the scientific community's readiness for the rapid analysis of new guests from space. 🛸📡🚫"
date: 2026-07-01T05:14:00.000Z
lang: en
url: https://xab.info/en/posts/aliens-didnt-call-seti-scanned-comet-3i-atlas-and-found-only-terrestrial-interference
tags: []
publisher: "XAB.info"
---

# Aliens Didn't Call: SETI Scanned Comet 3I/ATLAS and Found Only Terrestrial Interference

![SETI radar antennas at sunset, scanning the sky for signals from comet 3I/ATLAS](https://xab.info/media/2026/07/01/seti-proveril-kometu-3i-atlas-i-nashel-tolko-zemnye-pomehi/seti-proveril-kometu-3i-atlas-i-nashel-tolko-zemnye-pomehi-1.webp)

In July 2025, the astronomical community welcomed a new guest from the depths of space — comet 3I/ATLAS. This was only the third confirmed interstellar object in history to arrive in the Solar System from another stellar neighborhood. Following the famous 'Oumuamua (1I) and Comet Borisov (2I), this object sparked immense interest not only among astrophysicists but also among specialists at the SETI Institute, dedicated to the search for extraterrestrial intelligence.

### Searching for Technosignatures in Polar Regions

Interstellar objects are unique time capsules carrying matter formed around other stars. Their study helps scientists understand the evolution of planetary systems across the Galaxy. However, while the behavior of 3I/ATLAS corresponded to that of a natural celestial body, it did not rule out the hypothesis that something artificial might be hidden behind the rocks and ice. To test this theory, astronomers organized a large-scale search for radio signals.

### 74 Million Pulses and Zero Aliens

Specialists used powerful radio telescopes, specifically the Allen Telescope Array system, to monitor the object. Observations lasted more than seven hours in the range from 1 to 9 gigahertz. This spectrum was chosen for a reason: it is precisely in this range that narrowband radio signals are usually detected, which do not occur in the wild and are signs of a technological civilization.

The results of the initial scan amazed even skeptics: the equipment recorded about 74 million narrowband pulses. This number could have been a sensation if not for the next stage of work. Scientists conducted a thorough filtering of data, eliminating terrestrial noise and synchronizing signals with the trajectory of the comet's movement. As a result, out of millions of pulses, only 200 main candidates were selected.

However, the final analysis dashed hopes for contact. All 200 suspicious signals were of exclusively terrestrial origin. Their sources turned out to be satellites in orbit around our planet and ground-based equipment. Aliens did not call, and the comet turned out to be just a comet.

### Strict Limits and the Victory of Speed

Despite the absence of technosignatures, the experiment provided science with important data. Scientists established strict limits on the power of possible transmitters near 3I/ATLAS. Researchers completely ruled out the presence of radio transmitters with a power greater than $10^{110}$ watts on the object. This value is comparable to the power of ordinary household appliances, which finally confirms the natural status of the object.

The main result of the project was not so much the verification of the alien hypothesis as the demonstration of the speed of reaction of the scientific community. The Allen Telescope Array system was able to begin observations less than a day after the official announcement of the discovery of 3I/ATLAS. Such responsiveness proves that astronomers are fully ready for the rapid interception and comprehensive analysis of future interstellar visitors, which may turn out to be more than just chunks of ice and rock.