A strange and massive object is hurtling toward Earth — and it’s sparking a heated debate in the scientific community. While many researchers are calling it an ordinary comet, one leading Harvard physicist says it could be something far more unusual, possibly even artificial in origin.

The object, known as 3I/ATLAS, was first detected by NASA on July 1. Whenever a large object passes near our planet, speculation quickly swirls — is it a harmless space rock, or something designed by an advanced civilization? In this case, the answer isn’t so clear.

Why This “Comet” Doesn’t Add Up

More than 200 scientists have examined the data and concluded that 3I/ATLAS is most likely a comet. But Harvard astrophysicist Avi Loeb, known for his work on interstellar phenomena, strongly disagrees.

Loeb points out one glaring issue: the absence of a visible comet tail. “There were claims of a tail,” he explained, “but since 3I/ATLAS is accelerating and its current size is not much larger than the angular resolution of Earth-based telescopes, it is not easy to avoid fictitious elongation of the image as a result of the object's motion.”

Even more suspicious, the object shows no signs of gas emissions and follows a trajectory that aligns unusually well with the solar system’s orbital plane — behavior that is uncommon for natural comets.

The Loeb Scale and an Alarming Score

To assess its origin, Loeb applied his own metric — the “Loeb Scale” — which rates interstellar objects from 0 (definitely natural) to 10 (definitely technological, such as an alien craft). 3I/ATLAS scored a 6, meaning it is more likely engineered than naturally formed.

Loeb even floated a bold theory: the object could be a mothership releasing mini-probes toward Earth. “The more likely scenario from an engineering perspective involves a mothership that releases mini-probes which perform a reverse Oberth maneuver to slow down at perihelion and intercept Earth,” he wrote on his blog.

If his calculations are correct, these probes could reach Earth between November 21 and December 5, 2025. In his words: “It may come to save us or destroy us. We’d better be ready for both options and check whether all interstellar objects are rocks.”

No Tail, No Easy Answers

Images of 3I/ATLAS taken on July 4 and July 29 show no signs of the classic comet tail, further fueling speculation. To settle the debate, Loeb has suggested using NASA’s Juno spacecraft to intercept the object near Jupiter in 2026.

Meanwhile, he urges continuous monitoring: “The best we can do is monitor the sky with telescopes. It may well be that 3I/ATLAS is a natural comet. But even then, we have to check each and every interstellar object… for anomalous characteristics like non-gravitational acceleration with no cometary tail, artificial lights, or unusual shapes.”

Should Governments Prepare?

Loeb believes that if the object is not natural, governments worldwide should already be drafting a response plan. Whether 3I/ATLAS turns out to be a comet, an alien probe, or something entirely unexpected, the implications could be enormous for science — and for humanity’s future.