3I/ATLAS Is Leaving the Solar System Forever
Comet 3I/ATLAS, the third confirmed interstellar visitor, is making its final exit from the solar system. Skywatchers have a last chance to observe this rare event before the comet disappears indefinitely into space.
Unique Interstellar Visitor
First discovered in July 2025, comet 3I/ATLAS has intrigued astronomers with its unusual light fluctuations, distinctive composition, and hyperbolic trajectory. Unlike typical comets that orbit the Sun, 3I/ATLAS originates from beyond our solar system.
Trajectory and Departure
The comet is currently speeding away on a hyperbolic path that guarantees it will never return. NASA has confirmed its interstellar origin, placing it alongside 1I/ʻOumuamua and 2I/Borisov as the only known extrasolar objects passing through our neighborhood.
Perihelion and Speed
3I/ATLAS made its closest solar approach (perihelion) on October 29, 2025, passing about 1.4 astronomical units from the Sun, or roughly 130 million miles.
- Its speed exceeded 100,000 miles per hour during this perihelion.
- Global observatories monitored its dust composition to understand its origins from other star systems.
Viewing Opportunity
Observers in the Northern Hemisphere can view comet 3I/ATLAS in the pre-dawn sky until mid-December 2025, marking a once-in-a-lifetime chance to witness a true interstellar object.
"The comet made its closest approach to the Sun on 29 October 2025, passing about 1.4 astronomical units from the Sun — roughly 130 million miles," said NASA.
Expected Exit
Comet 3I/ATLAS is predicted to leave the solar system permanently by January 2026, disappearing into the vastness of deep space.
Author's summary: Comet 3I/ATLAS, a rare interstellar traveler, is departing the solar system permanently, offering skywatchers a unique final chance to observe it before it vanishes forever.