Does the scientific community as a whole share the notion that a newly discovered interstellar object 3I/ATLAS is an alien spacecraft heading to Earth for a "surprise attack" in November 2025? No, that's not true: The NASA website says that it's a comet and that it doesn't pose any risk to Earth. Three astronomers told Lead Stories that, as of this writing, the scientific community overwhelmingly shares this view. The scientist proposing the alien theory said he did so to challenge people to think, while, nevertheless, implying an interest in an influx of government money to fund that line of inquiry.
The claim appeared in a post (archived here and here) on TikTok on July 27, 2025, under the following caption:
Scientists at Harvard discovered an unknown object headed towards the Earth at 130,000 mph and its 15 miles in diameter and apparently is very unusual and possibly a space craft. #space #aliens
The narrator in the video continued:
Now they're saying it's going to be here by the end of November. They don't just think it's an object. They think it's a spacecraft coming to attack the Earth. It's called 3I/ATLAS, and they're worried about a surprise attack.
This is what the post looked like on TikTok at the time of writing:
(Image source: screenshot of a post by @knightfallen_angel on TikTok.com)
According to the NASA website (archived here), 3I/ATLAS was first discovered on July 1, 2025. The shape of its path, differentiating from orbit around the Sun, allowed astronomers to conclude that it's an interstellar object, the third known of that class.
While some of its characteristics are yet to be determined, the scientific community agrees that 3I/ATLAS is a comet, reads the NASA website:
...it has an icy nucleus and coma (a bright cloud of gas and dust surrounding a comet as it approaches the Sun). This is why astronomers categorize it as a comet...
The space agency additionally clarifies that, contrary to the posts on social media, 3I/ATLAS poses no danger to Earth:
Although the trajectory of the object brings it into the inner solar system, it won't come close to Earth. As the comet 3I/ATLAS journeys through the solar system, it won't come closer than 1.6 au (about 150 million miles, or 240 million kilometers) to our planet.
Despite this information being publicly available on a government website, many other posts were trending under the keywords "massive alien mothership approaching Earth": for example, here (archived here and here), here (archived here and here) and here (archived here and here). Some of them, specifically professor Avi Loeb (archived here), of Harvard University's Astronomy Department. Talking to a CBS affiliate (archived here and here) in late July 2025, he implied that the newly discovered object can be anything, including being a technological product of another civilization.
On August 1, 2025, Lead Stories contacted Loeb via email to clarify his views. On the same day, he wrote back, suggesting, among other things, that "3I/ATLAS might be an alien probe based on its unusually rare trajectory".
Loeb, however, went on to explain the alien theory was a kind of thought experiment, saying:
I laid out this possibility in order to encourage observers who are convinced that 3I/ATLAS is a comet to collect as much data as possible in an attempt to prove me wrong... Even if 49 out of the next 50 interstellar objects to be discovered by the Rubin Observatory will turn out to be comets or asteroids, the one outlier of technological origin might change the future of humanity.
He also pointed out that a draft version of one of his papers that has yet to undergo a peer review process -- "Is the Interstellar Object 3I/ATLAS Alien Technology?" (archived here) -- reads:
We strongly emphasize that this paper is largely a pedagogical exercise, with interesting discoveries and strange serendipities, worthy of a record in the scientific literature. By far the most likely outcome will be that 3I/ATLAS is a completely natural interstellar object, probably a comet...
At the same time, Loeb, who made similar claims rejected by the scientific community before (archived here), said:
Committees of mainstream scientists who decide how to allocate federal funds often resist investments in the search for extraterrestrial intelligence by arguing that it is too risky and might result in wasting taxpayers' money. But if these reviewers were humble enough to ask the taxpayers what they wish to spend their tax money on, they would find the search for extraterrestrial intelligence to be at the top of the priority list. Gatekeeping and ridicule are not the landscape I wished for when I started my scientific career 45 years ago...
Earlier, on July 31, 2025, Chris Lintott (archived here), a professor of astrophysics at the University of Oxford, referred to Loeb's theory of alien involvement as "absolute nonsense", continuing:
It's a comet, and no danger at all. It's exciting enough we get to study an object that formed before the Sun was born, and there's no need to invent stupid stories to get attention.
Two more astronomers told Lead Stories: The existing consensus among the members of the scientific community is that 3I/ATLAS is a comet.
Our observations have shown it's a comet. It doesn't come close to Earth: It's not on a collision course.
On August 1, 2025, David Jewitt (archived here), a UCLA professor of astronomy, told Lead Stories via email:
I've seen a lot of comets, and all I can say is that 3I looks to me like a comet.
There's more danger that your toaster oven will explode, assuming you have a toaster oven.
