The celestial body classified as 3I/ATLAS officially began its journey away from the inner regions of the planetary system, after reaching the point of closest proximity to Terra in December 2025.
This event marks a historic moment for astronomy, establishing 3I/ATLAS as the third scientifically validated interstellar object to cross our system. Diferentemente of the comets that reside in the Nuvem of
The passage allowed research teams to collect valuable information about the dynamics and chemistry of bodies formed in other stellar systems. Analysis indicates that the object carries preserved materials, functioning as a time capsule that offers scientists the chance to examine the raw material of exoplanets without the need to send probes light years away.
Trajectory monitoring and discovery
The initial identification of the celestial body was carried out by the ATLAS warning system, located at Chile, which detected the object crossing the orbit of Júpiter in July 2025. The instruments recorded an impressive speed, exceeding 200 thousand kilometers per hour, which served as the first indication that the body was not orbiting Sol.
Subsequent studies of orbital eccentricity confirmed the exotic nature of the visitor. With an eccentricity value above 1, mathematical calculations proved that the comet was just passing through, having been accelerated by unknown gravitational forces before momentarily interacting with our star.
The use of archival imagery was essential to reconstructing the path of 3I/ATLAS from mid-2025.
Chemical composition and X-ray emissions
During its passage through perihelion in October 2025, solar heat activated sublimation processes on the comet’s surface. Espectroscópios detected the release of gases and dust, creating a visible coma and an extensive tail. The Telescópio Espacial Hubble and the XMM-Newton observatory identified compounds such as methanol and hydrogen cyanide, common in comets but with distinct isotopic signatures.
A surprising discovery was the detection of X-rays emanating from the object, a first for interstellar visitors. Essa feature indicates complex energetic interactions between the solar wind and the comet’s temporary atmosphere, providing new data on the density and electrical charge of the released particles.
Observed physical characteristics
Several space missions, including probes orbiting Marte and Parker Solar Probe, have contributed to the creation of a detailed physical profile of 3I/ATLAS. Observations suggest that it is a primitive body, possibly older than Sol, that has endured the rigors of interstellar travel.
– The comet’s nucleus has an estimated diameter of between 440 meters and 5.6 kilometers.
– Analysis of the ejected dust revealed an abundance of oxygen, hydrogen and silicates.
– Foi recorded an anti-solar tail, the result of an optical phenomenon dependent on the terrestrial perspective.
– The reddish color of the coma suggests the presence of complex organic molecules processed by radiation.
Future route and comparison with predecessors
3I/ATLAS is now following an escape route that will take it to cross the orbits of gas giants. Astronomical projections indicate that the object will pass through the Júpiter region in 2026 and cross the Saturno orbit in 2028, before disappearing into the darkness of deep space.
Its trajectory, inclined in relation to the ecliptic plane, ensures that there will be no gravitational capture by the Sistema Solar. Comparado to previous visitors, ‘Oumuamua and