You now say this is not only an alien spaceship, but it’s nuclear-powered. Why are you saying that? >> 10 gigawatts of power. That’s the energy signature coming from the mysterious object 3I/Atlas. And it shouldn’t be possible. This interstellar traveler was supposed to be a simple comet, a dirty snowball reflecting the sun’s rays. But the latest high-resolution images show something else entirely. Instead of a classic tail, it has a strange glowing cocoon facing towards the sun. Its light profile is too steep. It’s fading too abruptly. According to Harvard’s Avi Loeb, we are not looking at nature. We’re looking at an object that appears to have an engine, and it’s flying a very deliberate path through our celestial backyard. 10 gigawatts of mystery. Something truly bizarre is flying through our solar system.

On July 1st, 2025, an automated telescope system called ATLAS, short for Asteroid Terrestrial-Impact Last Alert System, pinged an alert. It had spotted our third-ever interstellar visitor, an object from another star system, and it was given the designation 3I/Atlas. At first, the world of astronomy breathed a collective sigh of relief. Unlike the weird cigar-shaped ‘Oumuamua, this one looked like a regular comet. It had a fuzzy glow around it—a coma—which is exactly what you’d expect from a giant ball of ice and dust getting closer to the sun. The ice warms up, turns to gas, and creates a beautiful halo. Case closed. Right? Wrong. The thing nobody tells you is that the more we looked, the less sense it made. Many people are crazy about space, but even for seasoned astronomers, what came next was a shocker.

When the Hubble Space Telescope took a closer look, the images showed something that shouldn’t be possible. Comets have tails that are pushed away from the sun by solar wind and radiation pressure. But 3I/Atlas didn’t have a classic tail. Instead, it had a weirdly teardrop-shaped cocoon of dust that was elongated towards the sun. It was like seeing the smoke from a campfire blowing into the fire. This was the first major red flag. But then came the light itself. Avi Loeb, the former chair of Harvard’s astronomy department, and his colleague took a deep dive into the numbers, analyzing the brightness profile of this strange glow. What they found was jaw-dropping. The light from the coma faded incredibly steeply, much faster than the light from any known comet. You see, but not all things are what they seem. Loeb realized this steep light curve pointed to one unbelievable conclusion: The sun wasn’t the primary source of illumination. The object was lighting up the dust cloud from within. It was generating its own light, and the amount of power required was astronomical.

Loeb calculated the object was glowing with a continuous output of 10 gigawatts. To put that in perspective, that’s the energy equivalent of 10 full-scale nuclear power plants running at maximum capacity here on Earth. This isn’t a faint flicker. It’s a colossal beacon of energy in the cold darkness of space. This single fact completely flips the script. If it’s making its own light, then the initial size estimates were all wrong. The original model based on reflected sunlight suggested 3I/Atlas was enormous, maybe 12 miles across—twice the size of the asteroid that wiped out the dinosaurs. An object that big is incredibly rare. But if it has an internal reactor, Loeb’s calculation suggests the object itself could be tiny, perhaps smaller than 300 feet across. A small object producing that much energy is, scientifically speaking, unheard of in nature. It defies our understanding of physics. We simply don’t know of any natural process that allows a 100-meter rock to generate the power of a small nation.

The mystery only deepens from here. But its impossible energy source wasn’t the only secret it was hiding. A path of purpose. When an object travels for millions or even billions of years between the stars, you’d expect its path to be random. It should come in at any old angle from any direction. But 3I/Atlas is different. Its trajectory is suspiciously neat. The thing is, it’s traveling within the ecliptic plane—the flat, pancake-like disc where all the planets in our solar system orbit. The odds of a random interstellar object lining up so perfectly with our planetary plane are incredibly low—something like a 1 in 500 chance. It’s like throwing a dart from across a football field and having it land perfectly flat on the 50-yard line. It’s possible, sure, but it’s eyebrow-raisingly precise.

But the coincidences don’t stop there. The path of 3I/Atlas seems almost like a guided tour of our solar system. After swinging by the sun, its trajectory is set to take it remarkably close to several key planets. On October 3rd, 2025, it will have a blind date with Mars, passing within 18 million miles. This is close enough for the HiRISE camera on the Mars Reconnaissance Orbiter to get our best images yet. Then it continues on its journey, set for a close approach with Jupiter. Avi Loeb describes this trajectory as fine-tuned and deliberate. He raises a chilling possibility: What if this path wasn’t an accident? What if the object is mapping our system, observing our planets, or even deploying smaller probes? The idea sounds like science fiction, but the orbital mechanics are hard to ignore.

This is where the story gets even stranger. The James Webb Space Telescope made another bizarre discovery: The gas cloud around 3I/Atlas is made almost entirely of carbon dioxide with very little water. For a normal comet, this ratio is paradoxical. This unusual chemistry, combined with the lack of a water vapor tail, adds yet another layer to the mystery. Some scientists argue this just means it formed in a very different kind of star system. But Loeb offers a more provocative explanation: What if the object isn’t a comet at all, but a spacecraft, and the glow is its nuclear engine burning off a thin layer of interstellar dust and grime that has accumulated over its long journey? The CO2 could be part of this cosmic dust, not the core composition of the object itself. The evidence is mounting that we’re dealing with something far outside our normal experience.

So, if it isn’t natural, what could it possibly be? Breaking down the theories. So what is the truth about 3I/Atlas? The scientific community is deeply divided. On one side, you have the majority of astronomers who urge caution. They argue that we are witnessing a natural, albeit very strange, comet. The universe is a big place, and we shouldn’t be surprised to find objects from other star systems that don’t conform to our local rules. They suggest the weird glow could be from exotic ices we haven’t seen before, or the unusual composition is just a sign of its alien origins. They say calling it an alien probe is jumping to conclusions without enough evidence. To them, it’s an exciting puzzle, but one that likely has a natural explanation waiting to be discovered. They correctly point out that extraordinary claims require extraordinary evidence.

On the other side is Avi Loeb, leading a smaller but vocal group of scientists who believe we must consider the alternative. He argues that clinging to the comet explanation is like seeing a car and insisting it must be a funny-shaped horse because that’s all you’ve ever seen before. The list of anomalies is just too long to ignore: the internal power source, the precise trajectory, the lack of a cometary tail, the strange chemical signature. Loeb isn’t saying it’s definitely an alien spacecraft. What he is saying is that the possibility is high enough that we have to take it seriously. He created something called the Loeb Scale to rank interstellar objects, and he currently places 3I/Atlas at a four out of 10—not a certainty, but a significant possibility of being artificial.