3I/ATLAS Real Story: Brian Cox Says Comet Formed Before Our Planet

As speculation intensifies regarding the nature of the interstellar object 3I/ATLAS, Professor Brian Cox has issued a firm rebuttal to the viral theories suggesting it may be of alien origin.

Appearing on the StarTalk podcast, the physicist argued that while the object is scientifically profound, the public's fixation on extraterrestrial explanations is distracting from the more compelling reality of its natural origins.

A Natural Time Capsule

In a recent appearance on the StarTalk podcast, Cox sat down with host Neil deGrasse Tyson and comedian Chuck Nice to dissect the hysteria surrounding 3I/ATLAS. He wasted no time in dismantling the viral theories that suggest the visitor is an alien probe.

He argued that it is 'illogical' to leap to the conclusion that the object is a spacecraft. Cox branded these hypotheses as unfounded, stressing that all available evidence points to a simpler reality.

According to his assessment, 3I/ATLAS is an interstellar comet, composed of 'carbon dioxide and water ices and bits of other stuff.'

Cox expressed disappointment that misinformation is distracting the public from the genuine majesty of the situation. He believes that by chasing science fiction, we are ignoring a scientific reality that is 'more interesting.'

Prof Brian Cox Reveals The 'Fascinating' 7-Billion-Year Origin

For the physicist, the object's value lies in its immense age. Cox described 3I/ATLAS as a 'fascinating thing' with an estimated age of 7 to 8 billion years. This means the comet formed long before Earth existed, born in a 'distant star system' far older than our own sun.

He emphasised that this provides scientists and astronomy enthusiasts with an 'unprecedented opportunity.' We are currently witnessing material that has travelled across the void for aeons, only to grace Solar System for a brief moment.

Channelling the late astronomer Carl Sagan, Cox noted that the reality of a pre-Earth object visiting us is profound enough on its own.

'You know, that's what I think is what Carl Sagan mean,t that the reality of it that this is something that formed before the Earth formed, and visiting our solar system and going back into interstellar space is more interesting than trying to say that it's some kind of completely useless [aliens],' Cox explained during the StarTalk episode.

Trajectory and the 'Missed Exit'

To further highlight the absurdity of the alien theories, Cox and the StarTalk StarTalk team pointed to the object's trajectory. The comet will miss Earth by a massive margin—approximately 1.8 astronomical units, or 168 million miles (270 million kilometres).

'By the way, if it's an alien spaceship, it's not spending much time [here],' Cox joked, noting the wide berth.

Comedian Chuck Nice added levity to the discussion, quipping that the aliens simply 'missed their exit.' Cox continued the bit, imagining the aliens' perspective: 'Seven billion years. We'll go around again. We'll make a course correction and go around again. I'm sure it will be fine. Not much will have changed in only seven billion years.'

The Philosophical Divide: Cox vs Loeb

Cox's firm stance aligns with NASA's narrative, which aims to quell panic and clarify that the object poses no threat. Since October 2025, Cox has stuck to his guns, insisting the object is 'entirely natural'.

That puts him directly at odds with Harvard physicist Avi Loeb, who sees things differently. Ever since 3I/ATLAS was spotted back in July, Loeb has been pushing scientists to keep an open mind, arguing that the object's strange behaviour deserves a second look.

While Loeb has not definitively claimed it is aliens, his insistence on maintaining scepticism has fueled the very rumours Cox seeks to debunk. Despite the debate, Cox remains adamant that the object is on a hyperbolic orbit and will never return. As he told IFLScience, astronomers and casual observers are getting a brief glimpse of an ancient traveller before it disappears into the dark forever.