Archive · 8 Nov 2025
First Radio Signal Detected from Interstellar Object 3I/ATLAS Near Sun
Scientists have detected a radio signal coming from a space rock called 3I/ATLAS, which is not from our solar system.
It's like finding a message from another star!
The signal was picked up by a big radio telescope in South Africa.
This radio signal is made of tiny particles called hydroxyl radicals, which are like a natural scent from the rock.
This is the first time we've 'heard' 3I/ATLAS using radio waves.
This rock is very strange because it doesn't look like other comets, it barely has a tail.
A scientist named Avi Loeb thinks that 3I/ATLAS might be related to another mysterious radio signal from the past called the 'Wow!
Signal'.
He noticed that both came from roughly the same part of the sky.
He hopes that even bigger space missions, like one near Jupiter, might be able to listen for more signals from 3I/ATLAS in the future.
The MeerKAT radio telescope in South Africa detected radio absorption lines from interstellar object 3I/ATLAS.
The detected signal consists of hydroxyl radicals (OH molecules) at specific radio frequencies.
This marks the first radio detection from 3I/ATLAS since its discovery.
Scientist Avi Loeb noted the signal's Doppler shift and its unusual direction, similar to the 1977 Wow! Signal.
Future observations by the Juno spacecraft near Jupiter are planned to search for more radio signals from 3I/ATLAS.
- Who
- South African observatory (MeerKAT radio telescope) and Harvard scientist Avi Loeb
- What
- Detected the first radio signal, specifically OH absorption lines, from interstellar object 3I/ATLAS.
- When
- October 24, 2025
- Where
- Near the Sun
- Why
- Attempting to detect radio emissions from the anomalous interstellar object 3I/ATLAS, with a specific interest from Avi Loeb regarding its potential connection to the Wow! Signal.
Possibility of 3I/ATLAS Emitting Wow! Signal
Skepticism and Other Explanations
Directional Alignment
Possibility of 3I/ATLAS Emitting Wow! Signal
Avi Loeb's calculations suggest 3I/ATLAS's arrival direction coincides within 9 degrees of the Wow! Signal's direction, making a 0.6% chance of random alignment.
Skepticism and Other Explanations
While the alignment is noted, it is still considered a coincidence by many, and the Wow! Signal remains unexplained with no definitive link established.
Origin of Radio Signal
Possibility of 3I/ATLAS Emitting Wow! Signal
Avi Loeb theorizes that 3I/ATLAS could have sent the Wow! Signal.
Skepticism and Other Explanations
The detected radio signal is from hydroxyl radicals (OH molecules) emitted by 3I/ATLAS, a natural phenomenon, not necessarily evidence of artificial transmission.
- Interstellar Object
- 3I/ATLAS
- Observatory
- MeerKAT radio telescope (South Africa)
- Detected Signal
- Radio absorption lines by hydroxyl radicals (OH molecules)
- Detection Dates
- October 24, 2025 (successful); September 20 and 28, 2025 (unsuccessful)
- Angular Separation from Sun
- 3.76 degrees (at detection)
- Associated Scientist
- Avi Loeb (Harvard)
- Wow! Signal Connection
- Arrival direction within 9 degrees of Wow! Signal's 1977 detection