Astronomers have confirmed it — the mysterious object spotted flying through the outer solar system is not from around here. Say hello to 3I/ATLAS, the third known interstellar object to enter our solar system.
🌌 A Visitor from Beyond the Stars
Originally dubbed A11pl3Z, the object has now received its official name: 3I/ATLAS. The “I” stands for interstellar, indicating its origin from outside our solar system.
According to NASA, 3I/ATLAS is currently traveling between the orbits of Jupiter and the asteroid belt — roughly 416 million miles from the Sun. That’s more than 4.5 times the distance between the Earth and the Sun.
And it’s coming in hot.
At a staggering 130,000 miles per hour, 3I/ATLAS is blazing toward the inner solar system — "a thousand times over the speed limit on a highway," quipped Harvard astrophysicist Avi Loeb.
🛰️ Where Did It Come From?
"If you trace its orbit backward, it seems to be coming from the center of the galaxy, more or less," said Paul Chodas, director of NASA’s Center for Near Earth Object Studies. "It definitely came from another solar system. We don't know which one."
That speed and trajectory confirm its interstellar origins — no object bound to our Sun could move that fast.
☄️ What Is 3I/ATLAS?
Provisionally, 3I/ATLAS appears to be a comet, making it the second known interstellar comet after 2I/Borisov, which broke apart spectacularly in 2019. The first interstellar object ever spotted, 1I/'Oumuamua, had a strange, elongated shape and left scientists baffled in 2017.
Its glowing appearance likely comes from a coma — a cloud of gas and dust formed when sunlight heats the object. This makes size estimates tricky. If it were a rocky asteroid, it could be up to 12 miles wide, but as a comet, the actual solid core might be much smaller and hidden within a bright halo.
"You can’t infer the size of the solid object from the brightness of the coma," Chodas said.
🔭 Discovery and Observation
The story of 3I/ATLAS began on a telescope in Chile — part of the Asteroid Terrestrial-impact Last Alert System (ATLAS) — which flagged the object on Tuesday. Within hours, the Minor Planet Center and NASA's Jet Propulsion Laboratory confirmed it as a near-Earth object.
Soon, over 100 observations poured in from telescopes around the world, many noting signs of cometary activity. That led to its official designation as 3I/ATLAS.
🪐 What's Next?
Unlike 'Oumuamua, which slipped away after just a few weeks, 3I/ATLAS will be visible to astronomers for months to come. Its closest approach to the Sun will occur around October 30, at a distance of about 130 million miles, placing it inside the orbit of Mars.
“It’ll be easily observable for astronomers around the world,” Chodas said. “It should be visible well into next year to large telescopes.”
🛸 As it races through our solar system, 3I/ATLAS offers a rare and thrilling opportunity to study a visitor from the stars — a cosmic postcard from another world.
