The arrival of the interstellar object 3I/ATLAS has reignited one of the most profound debates in science: whether Earth's biological history is unique or the result of ancient extraterrestrial intervention.
While mainstream astronomers classify the visitor as a comet, Harvard physicist Avi Loeb argues that its trajectory and physical anomalies suggest it could be a technological artefact, potentially serving as a 'seed' carrier in a cosmic distribution network.
Harvard Scientist Suggests 3I/ATLAS Could Be an Alien 'seed'
According to Harvard scientist Avi Loeb, it is statistically improbable that Earth has existed in isolation for 4.6 billion years. The astrophysicist argues that we have likely been visited by extraterrestrial technology long before humanity began recording history.
'There were plenty of opportunities for residents of previous stars to visit our place,' Loeb stated. 'It really depends on their agenda. But if there is an interstellar gardener, then obviously it could have intervened....it could have seeded the various forms of life on Earth intentionally.'
🚨 Is 3I ATLAS just a comet... or something more? Why is NASA silent?
— Shambhu Patwa Dighwara wala (@djshmbhu30) November 30, 2025
Today we're talking about 12 mysteries of *3I ATLAS* that have led some scientists—notably renowned Harvard astrophysicist Avi Liob—to call it not just a comet, but a possible alien ship!
NASA has repeatedly… pic.twitter.com/Ih2GU6iJes
Loeb's theory rests on the idea of directed panspermia—the hypothesis that life exists throughout the Universe and is distributed by space dust, meteoroids, asteroids, comets, and planetoids. Unlike natural panspermia, which relies on chance collisions to transport microbes, directed panspermia implies agency.
He suggests that an 'ambitious gardener from an earlier star' could have utilised objects like 3I/ATLAS to impact life on Earth. The astrophysicist points to specific anomalies to support his claims. Recently, he noted that 3I/ATLAS boasts a 'heartbeat'-like pulse.
He argues this could provide evidence of artificial origins. Further, this could potentially point to the inner workings of a spaceship rather than a natural comet.
The Sceptical Consensus: Occam's Razor
Though Loeb's theories have gained traction within and outside the scientific community, mainstream consensus maintains that 3I/ATLAS is a comet. Experts agree with NASA's classification and observe that available data support this conclusion.
'It's acting just like a piece of rock and ice would,' said Leslie Looney, a professor of astronomy at the University of Illinois.
Pay attention to what we are looking at here 3i/Atlas.
— GREEN AYCE (@Green_ayceUSA) October 7, 2025
My take: 4 -7 orb like structures rotating around some energy source which is powering the craft(comet) 🧐#viral $atlas $3IATLAS #3IATLAS
Comet or Alien ship 👀 ?
#2027 simulation 👀 pic.twitter.com/ERZeY17FKL
According to Looney, 3I/ATLAS is displaying the classic characteristics of an interstellar comet. These objects are giant, dusty snowballs that create tails of gas and dust as they approach the Sun.
While he admits that 'We are seeing material from another solar system come swinging through our solar system,' and that this alone is amazing, he maintains a sceptic's view on the alien hypothesis.
Looney invokes the standard set by astronomer Carl Sagan: 'Extraordinary claims require extraordinary evidence.' For the majority of the scientific community, a 'heartbeat' signal or unusual trajectory is not yet proof of an alien manufacturer.
Technosignatures and Narrowband Signals
While the debate over 3I/ATLAS continues, other researchers are taking a broader approach to finding extraterrestrial life. Sofia Sheikh, a technosignature research scientist at the SETI Institute, utilises the Allen Telescope Array to listen for radio signals that are distinct from natural cosmic noise.
'Human technological signals often are really concentrated in their width,' Sheikh explained.
This distinction is critical. Natural cosmic phenomena—such as stars, quasars, and pulsars—emit radio waves across a broad spectrum of frequencies (broadband). If researchers were to identify 'narrowband' signals coming from deep space, it would be a strong indicator of non-human technology, as nature is not known to produce radio emissions confined to a single frequency.
However, the task is like finding a needle in a haystack made of needles. Sheikh notes that she must filter through 'all of the chaos and cacophony that is human technology on the Earth.'
Implications for Humanity if 3I/ATLAS Is a Warning
For science communicators like Hank Green, the distinction between wanting aliens to exist and proving they exist is vital. Countering the famous tagline from The X-Files, 'I want to believe,' Green asserts, 'I want to know.'
Loeb believes that dismissing objects like 3I/ATLAS as mere rocks could be a fatal error for humanity. He posits that these objects might be remnants of 'accomplished siblings of our family of intelligent civilisations' that may have already perished due to self-destruction.
'Many of them might have engaged in geopolitical conflicts on their rocky planet and perished by now,' Loeb wrote.
He argues that it behoves governments to reallocate military budgets toward space exploration. By becoming interplanetary ourselves, we might avoid the fate of these lost civilisations.
'If we continue along this path, we will not be remembered,' Loeb warned. 'And one way to change the priorities that we have is to realise that someone else did it (go interplanetary). If we get a visitor, it'll inspire us to imitate it, perhaps.'
