NASA Confirms A 20-Kilometer-Wide Object Flying Through Our Solar System!

On July 1, 2025, a telescope in Chile spotted something strange moving through the sky — fast and unfamiliar. It didn’t match the path of ordinary comets or asteroids we’ve seen before. This discovery was made by the NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) telescope in Rio Hurtado. After a few checks and confirmations, scientists realized what they were looking at wasn’t from our solar system at all.

This object has now been officially named 3I/ATLAS. The name follows a system: the “3” means it’s the third interstellar object ever found, the “I” stands for “interstellar,” and “ATLAS” is the name of the survey team that discovered it. Before this, only two interstellar objects had been confirmed — ʻOumuamua in 2017 and Borisov in 2019. So, finding 3I/ATLAS is a rare and exciting event for astronomers around the world.

Right now, the comet is about 420 million miles (or 670 million kilometers) from the Sun. It’s traveling extremely fast — around 130,000 miles per hour relative to the Sun — and will get even faster as it moves closer. That speed is a major clue that it didn’t come from inside our solar system. NASA’s Dr. Paul Chodas explained that its high velocity and unusual orbit clearly show it originated elsewhere, most likely from around another star.

So how do we know it’s really interstellar? Scientists traced its path backward and found it came from the direction of the Sagittarius constellation, pointing roughly toward the center of the galaxy. Dr. Chodas explained that something like a passing star probably knocked the comet out of its home system, sending it drifting through space — and eventually, by pure chance, near our solar system.

The comet won’t get anywhere close to Earth. In fact, when it reaches its nearest point to us in December, it will still be 160 million miles away. It will come closest to the Sun around October 30, at a distance of about 130 million miles — which is just inside Mars’ orbit. So, there’s no danger of impact, just a chance to learn from a rare visitor.

Even before the official discovery date, astronomers looked back at older images taken by telescopes around the world, including the Zwicky Transient Facility in California, and found that the comet had already appeared in images from as early as June 14. These “pre-discovery” photos helped scientists better calculate its path and confirm its unusual origin.

One of the turning points in identifying the object came from an amateur astronomer, Sam Deen. He went back through old ATLAS images and found more sightings, helping to confirm its path and speed. That allowed the International Astronomical Union’s Minor Planet Center to officially list it and give it a name.

Soon after the announcement, over 100 observations from telescopes around the world were reported. Some of these even noted the object showing signs of being a comet, not just a space rock. That means it has a coma, which is a cloud of gas and dust around the core — what we usually see as the “glow” of a comet.

Interestingly, even though 3I/ATLAS is far away, it’s brighter than other known interstellar objects. That brightness raised questions among astronomers. Dr. Avi Loeb, a Harvard astrophysicist known for his bold ideas (including suggesting ʻOumuamua might be an alien spacecraft), asked why it’s so bright. If the comet’s surface was dark like a rock, it would have to be about 12 miles wide to reflect that much light. But since it appears to be a comet, the brightness likely comes from sunlight reflecting off its gas and dust cloud — not the core itself.

Still, the exact size of the solid core remains unknown. As Dr. Chodas put it, “You can’t infer the size of the solid object from the brightness of the coma.”

That mystery is part of what makes this comet so exciting to study. It should stay visible to ground-based telescopes until September, after which it will pass too close to the Sun to be seen. But by early December, it will reappear on the other side, and astronomers will get another chance to observe it.

During this time, scientists hope to gather more data, including what kinds of elements and molecules are in its gas and dust cloud. Tools like the James Webb Space Telescope could help measure the heat coming from the surface, offering more clues about what it’s made of.

In contrast, the first interstellar visitor, ʻOumuamua, faded from view in just a few weeks, leaving more questions than answers. This time, astronomers have more time and better tools to investigate.

In the future, more interstellar objects may be found thanks to advanced telescopes like the Vera C. Rubin Observatory in Chile, which will soon start scanning the entire sky every few days. Until 2017, we had never seen anything from outside our solar system pass through — and now, in less than a decade, we’ve seen three.

For now, 3I/ATLAS continues its journey through our solar system — a quiet traveler from another star system, offering us a rare chance to study a piece of the universe far beyond our own.