After ʻOumuamua and 2I/Borisov a new interstellar object 3I/Atlas races through solar system at 60 km/s

Astronomers have confirmed the discovery of a rare interstellar object named 3I/Atlas, the third-ever known visitor from beyond our Solar System. Detected racing through space at a blazing speed of 60 kilometers per second, 3I/Atlas is believed to have formed in a distant star system and dislodged due to gravitational tugs during stellar encounters.

Initially spotted by Chile’s ATLAS survey on July 2, 2025, the object was traced back in archived telescope data to June 14. Measuring an estimated 10 to 20 kilometers wide, it appears to be the largest interstellar object ever discovered, though that could vary depending on its icy composition, which reflects more sunlight.

Peter Veres of the International Astronomical Union’s Minor Planet Center described the object as “fuzzy,” indicating comet-like activity. It likely has a short tail and emits gas, confirming its classification as a cosmic snowball, or comet.

3I/Atlas poses no danger to Earth. It will pass safely inside the orbit of Mars before swinging around the Sun on October 29, 2025, at its closest point (perihelion), and then exit the Solar System in the years to come.

Unlike asteroids and comets that orbit the Sun, its hyperbolic trajectory confirms it’s not bound to our star — a true interstellar interloper. Astronomers say it’s likely been wandering the galaxy since being ejected from its home system.

This is only the third confirmed interstellar object after ʻOumuamua in 2017 — which sparked speculation of alien origin — and 2I/Borisov in 2019. Scientists are now working urgently to learn more about 3I/Atlas, including its shape, rotation, and composition.

The object is currently near the distance of Jupiter from Earth, and its speed is significantly higher than that of previous interstellar visitors. Though it’s too fast and distant to intercept with a spacecraft, researchers see it as a unique opportunity.

“If we detect amino acids or organic compounds on such objects,” said astronomer Mark Norris, “it could strengthen the case for life-friendly conditions elsewhere in the universe.”

With new telescopes like the Vera C. Rubin Observatory coming online, astronomers hope that similar discoveries will become more common — possibly monthly sightings of interstellar guests just like 3I/Atlas.