It’s not every day that something from the far reaches of the galaxy barrels into our cosmic neighborhood, but that’s exactly what’s happening this year. Astronomers around the world are buzzing over the discovery of 3I/ATLAS, an interstellar object spotted last month (July 2025) as it hurtled toward the center of our solar system. This marks only the third time in history that scientists have observed such a visitor from beyond, and, as you might expect, the excitement is palpable.
3I/ATLAS is no ordinary rock. It’s captured the imagination of experts and the public alike, not least because of the wild theories swirling around its true nature. According to Futurism and other science outlets, Harvard astrophysicist Avi Loeb—well-known for his controversial views on extraterrestrial life—has once again stepped into the limelight. Loeb, who previously made headlines for suggesting that the 2017 interstellar visitor 'Oumuamua could be a relic from an alien civilization, isn’t shying away from bold speculation this time either.
So, what’s so peculiar about 3I/ATLAS? For starters, NASA’s Hubble Space Telescope captured images on July 21, 2025, showing the object glowing in a way that defies the usual playbook for comets. Instead of a soft, even halo of light, the glow appears concentrated—almost, Loeb says, like “a vehicle turning on its headlights.” That’s not the sort of thing you’d expect from a chunk of ice and rock drifting through space.
Typically, comets develop a coma—a hazy, luminous cloud of gas and dust—when they approach the Sun, and they sport a bright tail streaming away from the solar wind. But with 3I/ATLAS, things aren’t so straightforward. As Loeb noted in a recent blog post, “there’s no evidence for a bright cometary tail in the opposite direction,” a detail confirmed by Hubble’s observations. Some scientists have suggested that the dust is simply evaporating from the Sun-facing side, but even that doesn’t fully explain what’s going on.
After discussing the matter with his Harvard colleague, astrophysicist Eric Keto, Loeb put forth a theory: the “simplest interpretation” of 3I/ATLAS’s steep brightness profile is that its nucleus is producing most of the light. If that’s true, the object could be much smaller than previously thought—possibly around 300 feet long, according to Daily Star, instead of the estimated 12 miles. That would make it a close cousin in size to 'Oumuamua and 2I/Borisov, the two other interstellar objects that have passed through our solar system in recent years.
Of course, the question on everyone’s mind is, what could cause an object to emit its own light? Loeb has put two possibilities on the table, both fascinating in their own right. The first is that 3I/ATLAS is a “rare fragment from the core of a nearby supernova that is rich in radioactive material.” In other words, it could be naturally glowing because it’s packed with radioactive elements. However, Loeb himself concedes that this explanation is “highly unlikely.”
The second, more tantalizing theory is that 3I/ATLAS is a “spacecraft powered by nuclear energy, and the dust emitted from its frontal surface might be from dirt that accumulated on its surface during its interstellar travel.” Before anyone gets too carried away, Loeb is quick to add that this hypothesis “requires better evidence to be viable.” Still, it’s hard not to let the imagination run wild at the prospect of an alien probe zipping past Mars.
Most astronomers, it should be said, remain firmly in the camp that 3I/ATLAS is a comet. The consensus, as reported by Futurism and Daily Star, is that the object is likely composed of ice and dust, behaving oddly but not inexplicably. Yet, the lack of a visible tail and the peculiar light signature keep the door open—just a crack—for more exotic explanations.
Adding to the mystery, 3I/ATLAS is on a trajectory that’s rare by cosmic standards. The object is set to pass near Venus, Mars, and Jupiter, making its closest approach to Earth on December 17, 2025. Loeb has pointed out that the odds of a natural space rock taking such a path are less than 0.005 percent, which only adds fuel to the speculative fire.
The scientific community isn’t content to let this opportunity pass by. Loeb has urged NASA’s HiRISE team, which operates the powerful camera aboard the Mars Reconnaissance Orbiter, to train their instruments on 3I/ATLAS during its close pass by Mars in early October 2025. According to Loeb, “This morning, I encouraged the HiRISE team to use their camera during the first week of October 2025 in order to gather new data on 3I/ATLAS. They responded favorably.” If all goes according to plan, we could soon have unprecedented images and data, giving scientists the chance to study this cosmic interloper up close.
There’s a palpable sense of anticipation as the astronomical community prepares for 3I/ATLAS’s rendezvous with Mars. As ScienceAlert put it, “Scientists hope new images will reveal whether 3I/ATLAS is just a strange space rock—or proof that alien technology is closer than we think.” That’s the kind of statement that gets even the most skeptical stargazer’s heart racing.
Meanwhile, the debate continues. Some experts caution against reading too much into the unusual observations, pointing out that our understanding of interstellar objects is still in its infancy. After all, with only two prior examples—'Oumuamua in 2017 and 2I/Borisov in 2019—there’s hardly enough data to draw firm conclusions about what’s normal and what’s not for these cosmic visitors.
But Loeb’s willingness to challenge conventional wisdom and propose bold hypotheses has sparked a broader conversation about how we interpret the unknown. As he’s fond of saying, “When you hear hoofbeats, think horses, not zebras—but every once in a while, it’s worth checking for a zebra.” In the case of 3I/ATLAS, the astronomical community is checking carefully, and the world is watching with bated breath.
With October and December fast approaching, all eyes will be on Mars and the skies above. Whether 3I/ATLAS turns out to be a run-of-the-mill comet, a radioactive fragment from a stellar explosion, or something altogether stranger, one thing’s for sure: it’s already changed the way we think about our place in the universe. And who knows? The next chapter in this cosmic mystery might be just around the corner.
