NASA Responds To Claims That Interstellar Object 3I/ATLAS Is An Advanced Alien Spacecraft

NASA has responded to claims – popularized by Harvard professor Avi Loeb – that the interstellar object 3I/ATLAS is a spacecraft sent to the Solar System by an advanced alien civilization.

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On July 1, 2025, astronomers spotted an object moving through the Solar System at nearly twice the velocity of previous interstellar visitors ‘Oumuamua and Comet Borisov. The object, which was confirmed to be an interstellar comet with its own dusty coma, is far larger than the previous two, with an estimated nucleus (the rocky part of the comet, excluding its coma) of around 5.6 kilometers (3.5 miles).

Early work showed that it is of huge interest to scientists, beyond being the third confirmed interstellar visitor. For a start, it may have come from a different region of our galaxy altogether, and may be far older than any of the known bodies in our Solar System. 

So far, so interesting. But unfortunately, it appears we can't enjoy the beauty of an interstellar visitor without somebody invoking aliens. Soon after the object was discovered, and before we could take a proper look at it, Israeli-American theoretical physicist, cosmologist, and astronomer Avi Loeb suggested that it may be an interstellar probe sent by an intelligent species, potentially sent to destroy Earth.

In the first paper, which he states in a blog post is largely a "pedagogical exercise" and "fun to explore, irrespective of its likely validity", he posited that the object could be hostile, as outlined in the "Dark Forest" hypothesis. In short (though you should read the book on which it is based, you will not regret it), given the finite resources in the universe, any lifeform may want to pre-emptively attack any other form of life, before it becomes a threat to their own civilization. According to Loeb's paper, the object could be here for that purpose.

"3I/ATLAS achieves perihelion on the opposite side of the Sun relative to Earth. This could be intentional to avoid detailed observations from Earth-based telescopes when the object is brightest or when gadgets are sent to Earth from that hidden vantage point," Loeb writes on his blog.

"The optimal point for a reverse Solar Oberth maneuver to become bound to the Sun is at perihelion," he added. "It is this optimal breaking point for 3I/ATLAS that is obscured from our view by the Sun."

The paper goes on to claim that if the comet were a spacecraft, it would be able to make it to Earth using this maneuver by November or December 2025. 

"The consequences, should the hypothesis turn out to be correct, could potentially be dire for humanity, and would possibly require defensive measures to be undertaken (though these might prove futile)," the paper adds, in case anybody wasn't freaking out about the comet enough.

"[If] future data will indicate the absence of a cometary tail, we will be faced with the tantalizing possibility that it did not inherit a random velocity in interstellar space but instead was sent towards the inner solar system by design," he added in another blog post, "being a member of a rare population of massive interstellar objects."

While these are all odd words to read in scientific papers, it isn't too surprising, as Loeb made similar claims about the previous two interstellar objects, suggesting 'Oumuamua may be a light sail, and is known for such outlandish speculation. 

While there is plenty of online interest in Loeb's claims, there is little in the way of scientific interest. This is because, while it is certainly an interesting object, the more we look at it on approach, the more it looks like a comet.

“It looks like a comet. It does comet things. It very, very strongly resembles, in just about every way, the comets that we know,” Tom Statler, NASA’s lead scientist for Solar System small bodies, said to The Guardian about such claims.

“It has some interesting properties that are a little bit different from our solar system comets, but it behaves like a comet. And so the evidence is overwhelmingly pointing to this object being a natural body. It’s a comet.”

Scientific papers looking at the object have consistently found that it is a comet, the first we have spotted from outside our Solar System, and easily the fastest comet we have ever seen. It will be interesting to observe the object as it approaches, even though at its closest approach to the Sun, it will be out of our view. But NASA can state with quite a lot of confidence, given the observations that have taken place already, that the object is not a threat to the Earth, and is not secretly harboring alien technology to destroy us all. Thank you, NASA.