A newly discovered interstellar object, officially known as 3I/ATLAS, and provisionally labelled A11pl3Z or C/2025 N1, is the third confirmed object passing through our solar system from beyond. It was initially spotted by the ATLAS survey telescope in Chile on July 1, 2025, with pre-discovery images dating back to June 14.
Significance
Rare visitor: Only two other interstellar objects have ever been observed—‘Oumuamua in 2017 and comet 2I/Borisov in 2019. Unlocking cosmic secrets: Each such visitor gives scientists a rare glance into the composition of other star systems. It sheds light on the materials that form planets and comets.
Discovery
ATLAS telescope in Chile detected it July 1, 2025. Afterward, astronomers combed archival data from ATLAS units and the Zwicky Transient Facility in California, locating observations from June 14 onward. Over 100 observations have since been collected, using both professional and amateur telescopes.
Trajectory & Speed
It follows an extremely hyperbolic (open) path, confirming it’s not gravitationally captured by our Sun. Currently ~4.5 AU (~670 million km) from the Sun, it’s racing inward at ~60 km/s relative to the Sun (≈37 mi/s). Closest approach to the Sun (perihelion) is expected around October 29–30, 2025, at ~1.36–1.4 AU—just inside Mars’ orbit.
Danger to Earth
Absolutely no threat: Will remain at least ~1.6 AU (≈150 million miles) from Earth. Travels between Earth and Mars with no risk of collision.
Comet or asteroid
Exhibits tentative cometary activity: a marginal coma and a short tail has been detected. Likely icy rather than rocky—more akin to 2I/Borisov than rocky ‘Oumuamua.
Next in the cosmic journey
Observation window: Visible from ground-based telescopes until September before disappearing behind the Sun.Reemergence: Expected to return to view in December 2025 after passing behind the Sun.Scientific potential: Astronomers anticipate monitoring its brightness, velocity, size, and composition—especially via livestreams by projects like the Virtual Telescope.
3I/ATLAS represents a rare cosmic messenger from another star system. Its hyperbolic path, icy composition, and safe yet intriguing trajectory make it a prime target for observation. As the third known interstellar object, it not only deepens our understanding of extrasolar planetary systems, but also shows how enhanced sky surveys and data analysis are transforming our ability to spot these fleeting travelers.
