The interstellar comet 3I/ATLAS passed through perihelion without fragmentation, according to images captured on November 11, 2025 by the Nordic Optical Telescope, located in La Palma, Spain. Astronomers David Jewitt and Jane Luu recorded the object with a tail directed away from the Sun, indicating continuous release of materials. This integrity defies previous calculations that predicted disintegration due to intense sublimation of ice.
The observation occurred after the comet completed its closest approach to the Sun, on a hyperbolic trajectory that confirms its origin outside the Solar System. Initially detected on July 1, 2025 by the ATLAS system in Chile, 3I/ATLAS is the third interstellar object identified.
- Composition includes high concentration of carbon dioxide in the coma, observed by the James Webb Space Telescope.
- Trajectory does not orbit the Sun, allowing exit from the system after passage.
- Radio signals picked up by MeerKAT in South Africa at frequencies of 1.665 GHz and 1.667 GHz.
Recent object observations
Images from the Nordic Optical Telescope show the preserved nucleus. The tail remains visible, proving volatile activity.
Researchers analyze data to understand thermal resistance. The perihelion required energy greater than initial estimates to maintain the structure.
Composition and anomalies detected
3I/ATLAS has a coma dominated by CO₂, different from solar comets. This feature was confirmed by JWST spectroscopy.
Hydroxyl radicals generate radio absorption lines, marking the first detection of an extrasolar object. The phenomenon derives from the sublimation of ice.
Studies indicate formation in another star system, with ejection millions of years ago. Hyperbolic velocity prevents gravitational capture by the Sun.
Emitted radio signals
The MeerKAT radio telescope recorded emissions in November 2025. The frequencies correspond to hydroxyl transitions. This capture represents progress in interstellar astronomy. Teams prepare continuous monitoring.
Planned future trajectory
The comet will approach Jupiter in March 2026, at around 50 million kilometers. Observations are scheduled by the International Asteroid Warning Network.
The passage will allow additional gravity and composition measurements. Data will help refine modelsof origin.
Early detection and classification
The ATLAS system identified the object in July 2025 in Río Hurtado. Analysis confirmed a hyperbolic trajectory. Classified as 3I, it joins 1I/’Oumuamua and 2I/Borisov as interstellar. The extensive coma facilitates optical tracking.
Persistent volatile activity
The release of gases keeps the tail active post-perihelion. This suggests larger-than-expected volatile reserves.
Scientists adjust size and density parameters based on the images. The object continues to wander outside the Solar System after interacting with Jupiter.
