NASA confirms that comet 3I/ATLAS, discovered on July 1, 2025 by the ATLAS telescope in Chile, follows a hyperbolic orbit and will leave the Solar System after passing through perihelion. The object, the third interstellar identified, reached the closest point to the Sun on October 29, at 1.4 astronomical units (210 million km). Its speed increased to around 244 thousand km/h.
The comet will approach Earth in December at 1.8 astronomical units (270 million km), without risk of collision. Composition rich in carbon dioxide and absence of typical tail generate scientific interest. Observations continue to understand an origin estimated between 7 and 14 billion years ago.
- Current speed: 244 thousand km/h.
- Perihelion: October 29, 2025.
- Minimum distance from Earth: 270 million km.
Unusual chemical composition
James Webb Telescope detected CO2 concentration eight times higher than water in the 3I/ATLAS coma. Data collected in August reveals carbon monoxide and hydroxyl vapors.
These elements indicate formation in a cold and distant environment. Lack of visible tail differentiates the object from comets like 2I/Borisov.
Coordinated monitoring
NASA coordinates observations with Hubble telescopes and space missions. Mars Express recorded data in October.
Comet became invisible during solar conjunction. Will return to visibility in December on professional equipment only.
International asteroid warning network conducts training to refine orbital calculations. Passage of Venus occurs in November at 97 million km.
Interstellar origin confirmed
Hyperbolic orbit has an eccentricity greater than 6. Age of the object exceeds that of the Solar System.
Analysis suggests ejection from another star billions of years ago. Gravitational interactions with the Sun alter the current trajectory.
Global Observation Campaign
Observatories in Chile, Hawaii and Australia participate in monitoring that began in November. Hubble images in July show a reddish coma rich in silicates.
Scientific contributions
The 3I/ATLAS study allows us to advance knowledge about interstellar chemistry. Presence of organohalogenated compounds challenges traditional comet models.
The absence of iron linked to nickel questions known formations. Data up to January 2026 will help define the final trajectory.
NASA confirms that comet 3I/ATLAS, discovered on July 1, 2025 by the ATLAS telescope in Chile, follows a hyperbolic orbit and will leave the Solar System after passing through perihelion. The object, the third interstellar identified, reached the closest point to the Sun on October 29, at 1.4 astronomical units (210 million km). Its speed increased to around 244 thousand km/h.
The comet will approach Earth in December at 1.8 astronomical units (270 million km), without risk of collision. Composition rich in carbon dioxide and absence of typical tail generate scientific interest. Observations continue to understand an origin estimated between 7 and 14 billion years ago.
- Current speed: 244 thousand km/h.
- Perihelion: October 29, 2025.
- Minimum distance from Earth: 270 million km.
Unusual chemical composition
James Webb Telescope detected CO2 concentration eight times higher than water in the 3I/ATLAS coma. Data collected in August reveals carbon monoxide and hydroxyl vapors.
These elements indicate formation in a cold and distant environment. The absence of a visible tail differentiates the object from comets such as 2I/Borisov.
Coordinated monitoring
NASA coordinates observations with Hubble telescopes and space missions. Mars Express recorded data in October.
Comet became invisible during solar conjunction. Will return tovisibility in December only on professional equipment.
International asteroid warning network conducts training to refine orbital calculations. Passage of Venus occurs in November at 97 million km.
Interstellar origin confirmed
Hyperbolic orbit has an eccentricity greater than 6. Age of the object exceeds that of the Solar System.
Analysis suggests ejection from another star billions of years ago. Gravitational interactions with the Sun alter the current trajectory.
Global Observation Campaign
Observatories in Chile, Hawaii and Australia participate in monitoring that began in November. Hubble images in July show a reddish coma rich in silicates.
Scientific contributions
The 3I/ATLAS study allows us to advance knowledge about interstellar chemistry. Presence of organohalogenated compounds challenges traditional comet models.
The absence of iron linked to nickel questions known formations. Data up to January 2026 will help define the final trajectory.
Passage by Jupiter is scheduled for March 2026 at 54 million km. Speed must reach 270 thousand km/h near Earth.
