Nasa – Foto: Tada Images / Shutterstock.com
NASA activated the planetary defense protocol after detecting unexpected variations in the brightness and trajectory of comet 3I/ATLAS, an interstellar object crossing the Solar System. The U.S. space agency, in collaboration with the International Asteroid Warning Network (IAWN), issued the alert through the Minor Planet Center at Harvard to coordinate global observations. The comet, discovered in July 2025, poses unique challenges in orbital prediction, prompting preventive measures despite no immediate risk to Earth. This mobilization includes a technical training campaign scheduled for the coming months.
Astronomers recorded an “anti-tail” on the comet, with particle jets directed toward the Sun instead of away, distorting orbital calculations. Telescopes like Hubble and James Webb captured images revealing this peculiarity, observed for the first time in an extrasolar visitor. The IAWN emphasized the need to refine astrometric methods for objects with intense gas and dust release.
Orbital measurement challenges
Gas release from 3I/ATLAS shifts its brightness center, complicating position estimates. Observatories in various countries will participate in simulations to standardize data. This distortion affects accuracy by up to 20% for similar comets, according to initial reports.
Orbital dynamics experts plan adjustments to tracking algorithms. The workshop set for November 10 will gather technicians to discuss these adaptations. The global campaign aims to reduce errors in hyperbolic trajectories like the comet’s.
Origin and speed of the visitor
3I/ATLAS travels at over 210,000 km/h, confirming its interstellar origin. Discovered by the ATLAS telescope in Chile, it follows ‘Oumuamua and 2I/Borisov as the third recorded case. Its orbit will reach perihelion on October 30, 2025, near Mars’ orbit.
Models indicate the nucleus measures between 320 meters and 5.6 km in diameter. The excessive speed accelerates material emission, detected at 450 million km from the Sun. Astronomers estimate its age at over seven billion years, predating the Solar System.
Chemical composition unveiled
James Webb data show a coma dominated by carbon dioxide, eight times higher than water. This ratio exceeds known variations in solar comets by six times. The analysis confirms OH emission at high distances, indicating early activity.
Researchers extract remote samples in a race against time. The composition suggests origins in distant systems beyond the Milky Way. Ground-based telescopes complement space observations to map rare elements.
Global observation campaign
The IAWN organizes exercises from November 27, 2025, to January 27, 2026. Telescopes in Hawaii, Chile, and Europe will focus on the comet to validate protocols. This marks the first inclusion of an interstellar object in defense campaigns.
- Involvement of agencies like ESA and Asian observatories;
- Emphasis on real-time data integration;
- Tests of responses to unpredictable orbital deviations.
The effort enhances surveillance against future threats, with no current direct impact.
Significance of technical cooperation
Though 270 million km from Earth, the case tests rapid response systems. NASA views 3I/ATLAS as a chance to study interstellar materials in detail. The mobilization strengthens international partnerships in astrometry, focusing on collective precision for rare events. This framework enables coordinated responses to atypical bodies, incorporating lessons from missions like DART. In the long term, the data will contribute to models of external planetary formation, expanding knowledge about the cosmos beyond the Solar System. The lack of immediate risk does not diminish the exercise’s value, preparing agencies for complex scenarios.
Predicted trajectory details
The comet will head toward Jupiter before exiting in 2026. Its hyperbolic path avoids collisions but requires ongoing monitoring.
