Comet 3I/ATLAS was first observed in late June 2025, and NASA confirmed its interstellar origin in early July. The comet has some strange properties: its extraordinary speed and unusual trajectory suggest it originated in a star system outside our solar system.
The comet is the third celestial body wandering in the solar system that is believed to have originated around another star. The other two interstellar objects were 1I/’Oumuamua, discovered in 2017, and 2I/Borisov, discovered in 2019.
The cosmic visitor is currently on a months-long journey through the inner solar system. According to NASA, the comet passed closest to Mars on Friday, October 3, 2025, and is now on its way to perihelion (closest point to the sun) on October 30.
After that, 3I/ATLAS will make its way back into interstellar space and will pass Jupiter in March 2026, before disappearing from our view forever. The comet poses no threat to Earth.
While 3I/ATLAS’s current path through the solar system is relatively well-defined, determining where the object came from is much more difficult. The comet is traveling at a speed of about 210,000 kilometers per hour, a record for interstellar objects. Such a speed is likely the result of gradual acceleration over millions or even billions of years.
During that time, its path has been repeatedly affected by the gravitational pull of numerous stars in the Milky Way galaxy. Just as NASA uses the gravity of planets to accelerate spacecraft, this comet may have been repeatedly deflected from its original path by the gravity of massive stars.