Interstellar comet 3I/ATLAS begins fragmentation as it approaches the Sun at 1.4 AU
The interstellar comet 3I/ATLAS, discovered in July 2025, showed the first signs of fragmentation this Thursday, October 30, 2025. The object, originating from another stellar system, reaches perihelion 1.4 astronomical units from the Sun, around 210 million kilometers. The intense heat accelerates the sublimation of volatile ices, releasing gases and dust in jets.
Astronomers from NASA and the European Space Agency monitor the phenomenon in real time. The hyperbolic trajectory confirms the origin external to the Solar System. The core, estimated to be less than a kilometer in size, faces increasing instability.
- Hubble and James Webb Telescopes capture emissions of carbon dioxide and nickel vapor.
- The elongated coma expands to thousands of kilometers.
- Speeds greater than 60 km/s prevent gravitational capture.
Hyperbolic trajectory confirms single pass
The 3I/ATLAS follows an orbit that takes it to cross the Solar System without return. Discovered close to Jupiter’s orbit by the ATLAS telescope in Chile, the comet has traveled millions of years since its origin.
Experts indicate ejection due to gravitational interactions with massive stars. The current speed guarantees definitive exit after perihelion.
Chemical composition reveals distant origins
Spectroscopic analyzes identify rare organic molecules in the nucleus. Nickel vapor suggests shapetion in cold regions, far from intense stellar radiation.
The presence of hydrogen cyanide allows comparisons with comets 1I/ʻOumuamua and 2I/Borisov. These compounds preserve information about planetary processes in other systems.
Monitoring captures changes in real time
Telescopes in Hawaii and Chile provide daily data on activity. Missions to Mars, such as Trace Gas Orbiter, record images from 30 million kilometers away.
The brightness varies between magnitudes 12 and 14, requiring equipment with an aperture of 200 mm. The central coma hides the nucleus in an indistinct spot.
Signs of collapse increase with heat
Fissures in the surface cause sudden ejections of material. Similar outbursts occurred in 2I/Borisov, generating smaller fragments. The increase in temperature accelerates sublimation, with the potential for complete core rupture within the next few hours.
International collaboration processes data
NASA coordinates efforts with ESA for real-time spectral analysis. Satellites such as GOES-19 captured variations during the solar conjunction on October 21. Australian institutions contribute modsublimation links. Data indicates release of dust equivalent to millions of particles.
Differences highlight unique dynamics
Dust plumes point towards the Sun, unlike traditional tails. The volatile-rich composition indicates cold molecular cloud origins.
3I/ATLAS approaches Mars’ orbit before exit, offering data on galactic dynamics.
Spatial observations show coma expansion
July Hubble images reveal teardrop-shaped dust 445 million kilometers away. Sublimation ejects fine particles pressed by radiation. Larger particles form tails observable in advanced telescopes. Dynamics accelerate disintegration at 1.4 AU.
Forecasts indicate post-perihelion weakening
The comet visually weakens as it moves away from the Sun from November onwards. Models predict a loss of up to 20% of mass if there is no total collapse. The minimum distance to Earth, 270 million kilometers, eliminates risks. The focus remains on collecting scientific data.
