Avi Loeb Reveals 3I/ATLAS' Anti-Tail Wobble Like a Cosmic Lighthouse

Harvard astrophysicist Professor Avi Loeb has disclosed that the interstellar object 3I/ATLAS exhibited a strange wobble in its anti-tail before perihelion, acting almost as a cosmic lighthouse.

The discovery, which Loeb wrote about on his Medium blog, is one of many involving the mysterious visitor, an object outside our solar system.

The anti-tail is a stream of material that curves out towards the sun, measuring only a few degrees wide, and it was found to vibrate at a period of 7.74 hours in July and August 2025. It is this rhythmic motion that implies that the jet base is not aligned with the poles of the nucleus's rotation axis by more than eight degrees, resulting in the jet precessing along a cone as the nucleus rotates.

The 14th Anomaly

Loeb has termed this behaviour the 14th anomaly about 3I/ATLAS; several other anomalies have been previously noted, including that the axis of rotation directly faces the Sun. Loeb observed in his analysis that it is extremely peculiar that the tail is aligned with the rotation axis, unlike natural comets, which usually have tails formed by solar radiation.

This wobble was not expected of a naturally occurring cometary jet, as Loeb wrote. It suggests that 3I/ATLAS could be exhibiting behaviour associated with technological causes.

A Cosmic Lighthouse Effect

The wobble was compared to a lighthouse beam sweeping through space, and the oscillation of the anti-tail to a periodic signal. Had the jet been artificially oriented, it could have served as a beacon visible at astronomical distances. Loeb had also argued earlier that peculiar aspects of interstellar objects, including Oumuamua, could indicate the presence of technological artefacts, rather than natural phenomena.

The comparison of the lighthouse highlights how 3I/ATLAS can be a source of signal, both deliberate and incidental. This periodicity of the wobble, together with its alignment, makes it distinct from the chaotic outgassing commonly observed in comets.

Scientific Controversy Increases

The finding has drawn controversy among the astrophysicists. Other scientists believe the wobble may be due to natural mechanisms, including sunlight-induced sublimation of ice pockets. Loeb, however, refutes it by suggesting that the accuracy of the alignment and the consistency of the oscillation are hard to attribute to haphazard natural action.

Critics warn against jumping to conclusions regarding the origins of technology, as extraordinary claims need extraordinary evidence. However, Loeb asserts that any abnormalities such as these ought to be explored exhaustively rather than avoided.

The discovery of anti-tail wobble by Professor Avi Loeb in 3I/ATLAS has reignited the debate over the nature of interstellar visitors. The rhythmic movement along the axis of rotation can be compared to a lighthouse of the universe, washing over the heavens. While sceptics remain cautious, the anomaly serves as a stark reminder of the unknown beyond our known universe and of what could challenge our understanding of the cosmos.

As Loeb himself argues, we must follow the evidence wherever it leads. In 3I/ATLAS, the indications are of behaviour never witnessed before, and possibly of a finding that could transform the way mankind views itself and its role in the universe.