Astronomers spot first ‘radio signal’ from interstellar comet 3I/ATLAS

Astronomers have detected the first-ever radio signal coming from the interstellar comet 3I/ATLAS as it travels halfway through its one-way journey across our solar system. While this might sound like proof of alien activity, scientists say it’s actually the opposite — the signal is completely natural.

What is 3I/ATLAS?

3I/ATLAS is only the third interstellar object (ISO) ever found passing through our solar system. It was first spotted in July, moving toward the sun at over 130,000 mph (210,000 km/h). Scientists believe it was thrown out of another star system in the frontier region of the Milky Way around 7 billion years ago.

Some people, including Harvard astrophysicist Avi Loeb, have claimed the comet could be an alien spacecraft, similar to the earlier theory about ‘Oumuamua, the first interstellar object ever discovered. However, experts say there’s no evidence to support this idea.

The Real Cause of the Radio Signal

When scientists using South Africa’s MeerKAT radio telescope detected the “radio signal” from 3I/ATLAS, some expected it to be a message from aliens. But the signal turned out to be natural radio emissions caused by hydroxyl radicals (OH molecules) in the comet’s coma — a cloud of gas around it.

These molecules form when water molecules break apart as the comet gets close to the sun, a process known as outgassing. This clearly shows normal comet activity.

NASA had already seen water spraying from the comet “like a fire hose” in early October, and now the radio data confirms that sunlight is breaking down that water — something expected when a comet reaches perihelion (its closest point to the sun).

Other Observations

The signals were first detected on October 24, right after 3I/ATLAS passed behind the sun. During this time, the comet became brighter and even changed color temporarily. It appeared to lose its tail but later showed it was still intact.

Although the comet shows some strange features — such as a bright surface, excess carbon dioxide, and an unusual “anti-tail” — scientists have logical explanations for all of these. Most agree that 3I/ATLAS is a natural object, not an alien craft.

Related Theories Debunked

Another rumor linked to 3I/ATLAS was that a newly spotted object, C/2025 V1 (Borisov), might be a probe released by the comet. Astronomers quickly dismissed this, confirming it’s just an ordinary solar system comet.

Claims that 3I/ATLAS exploded because of mass loss were also proven false by new observations.

Final Thoughts

In short, the first radio signal from an interstellar comet is an exciting scientific discovery — but it’s not a sign of aliens. Instead, it gives astronomers a better understanding of how ancient comets behave when they pass close to the sun.

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