Avi Loeb Suggests 3I/ATLAS Could Be Carrying Life to Seed Earth — Not Just a Comet

The universe is vast, and the search for extraterrestrial life often focuses on distant exoplanets. However, a provocative new idea from renowned astrophysicist Avi Loeb suggests we look closer to home.

Loeb proposes that 3I/ATLAS, an intriguing interstellar object, may not be merely a comet, but could be transporting life capable of seeding our planet.

The Mystery of Interstellar Visitor 3I/ATLAS

A strange celestial body, the interstellar object 3I/ATLAS, is currently travelling through our solar system. Its sunward tail and distinct make-up have puzzled researchers. These unique traits have sparked discussion of the possibility that the comet has a non-natural origin.

Against this backdrop of speculation, Harvard's Avi Loeb has put forward a striking idea: he suggests that 3I/ATLAS could well be of alien origin, and that this occurrence would not mark the first time extraterrestrials have visited our planet.

The Theory of Cosmic' Seeding'

In a truly groundbreaking proposal, Loeb suggested that interstellar objects, such as 3I/ATLAS, may actually be vessels dispatched by advanced cultures to deliberately 'sow' life on Earth, The New York Post reported.

Loeb, a distinguished astrophysicist, has noted several unexpected characteristics regarding the interstellar object 3I/ATLAS as it travels through our solar system. Based on these observations, he proposed that the object might not have formed naturally.

The Avi Loeb Hypothesis

Loeb suggests that the uncommon path and physical qualities of 3I/ATLAS could point to it being a product of technology—perhaps serving as a 'seed' that conveys life into a broader network.

'There were plenty of opportunities for residents of previous stars to visit our place,' Loeb told the Post. '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.'

Writing on his Medium blog, the researcher argued it is unlikely that over the 4.6 billion years of Earth's existence, we have not encountered at least one cosmic trespasser.

'I explained that meter-scale rocks from interstellar space may impact the Earth roughly once per decade, adding up to half a billion such collisions over the Earth's history,' he wrote. 'If any of these interstellar rocks carried resilient forms of life that survived the interstellar journey, Earth could have been exposed to extraterrestrial forms of life.'

Historical Blind Spot: The Limits of Human Observation

Given that most stars came into existence a billion years before the Sun, the researcher asserted that an 'ambitious gardener from an earlier star' would have possessed more than enough time to influence the development of life on our world.

'We often consider the history of Earth as isolated from its galactic environment, but this may not be the case,' said Loeb. He added that we probably lack any proof of such a cosmic arrival, given that recorded human history spans only 6,000 years.

He also mentioned that we have only been closely watching the sky for a fraction of that time. 'In terms of interstellar objects, it's only over the past decade that we started finding them,' Loeb told the Post, stating that our ability to spot extremely distant interstellar matter is somewhat restricted by current technology.

Interstellar Object 3I/ATLAS Causes a Stir

Since its detection in July, the interstellar object 3I/ATLAS has become a cosmic phenomenon, with every major space agency directing observational assets towards it to gather more information. This intense focus is due, in part, to its closest approach to Earth on 19 December.

Yet, despite the scientific speculation surrounding the object, NASA officially referred to it as a comet when it released related data last month.

To date, our solar system has recorded just three interstellar visitors: 1I/ʻOumuamua in 2017, 2I/Borisov in 2019, and 3I/ATLAS in 2025. 3I/ATLAS is currently travelling at 244,800 km/h, a velocity equivalent to about one-third of NASA's Parker Solar Probe's peak speed.

More Than a Comet: The Irregularities of 3I/ATLAS

Loeb points to several irregularities—including a retrograde orbit, an unusual metal make-up, and unexplained acceleration—which suggest the object may be more than a conventional comet. More recently, he proposed that 3I/ATLAS exhibits a rhythmic 'heartbeat' pulse, which he believes could provide evidence of its artificial construction.

'We may have a family of technological civilisations like ours or intelligence civilisations that we are not aware of,' he told the Post. 'These are siblings that we have, and the most accomplished among them are the ones that managed to leave their home planet with the birth planet that hosted them early and spread them.'

'I explained that meter-scale rocks from interstellar space may impact the Earth roughly once per decade, adding up to half a billion such collisions over the Earth's history,' he wrote in his blog on Medium.

'If any of these interstellar rocks carried resilient forms of life that survived the interstellar journey, Earth could have been exposed to extraterrestrial forms of life.' This theory by Loeb is grounded in directed panspermia, the concept that life exists throughout the universe and is intentionally distributed by celestial bodies like space dust, asteroids, comets, and meteoroids.

'We often consider the history of Earth as isolated from its galactic environment, but this may not be the case,' said Loeb.