NASA activates planetary defense protocol for interstellar comet 3I/ATLAS with orbital variations detected in 2025

The American Space Agency (NASA) activated the planetary defense protocol this week, after detecting changes in the trajectory and brightness of the interstellar comet 3I/ATLAS. The object was discovered on July 1, 2025 by the ATLAS telescope, located in Río Hurtado, Chile. There is no immediate risk to Earth, but variations complicate orbital predictions, requiring global monitoring coordinated by the International Asteroid Warning Network (IAWN).

The comet follows a hyperbolic orbit, confirming its origin outside the Solar System, and reached perihelion on October 30, 2025, close to the orbit of Mars, around 210 million kilometers from the Sun. This proximity intensified gas and dust emissions, which displace the center of luminosity and generate deviations of up to 20% in measurements.

Astronomers from institutions such as the Minor Planet Center, at Harvard, participate in the observations to refine the calculations. The collaboration involves ground-based and space telescopes, aiming to prepare responses to unpredictable trajectories in future events.

Brightness variations and tails observed

Hubble and James Webb Telescopes have captured images of the anti-solar tail on comet 3I/ATLAS, a rare formation where particles are ejected toward the Sun.

This characteristic, observed byThe first time an interstellar visitor changes the center of brightness and complicates position estimates. Jets of gas and dust act as irregular propellants, accelerating the object beyond 210,000 km/h.

The data indicate that cometary activity began early, more than 450 million kilometers from the Sun, suggesting an ancient and resilient core.

Chemical composition revealed by space probes

The James Webb Space Telescope identified a coma rich in carbon dioxide, with levels eight times higher than water, surpassing variations in solar comets.

This unusual composition points to formation in distant systems, possibly in the center of the Milky Way, more than seven billion years ago. The core measures between 320 meters and 5.6 kilometers in diameter, with hydroxyl (OH) emissions detected at great distances.

Complementary analyzes from ground-based telescopes map rare elements, such as reddish dust, which evolve with solar proximity. These findings refine models of external planetary formation.

Researchers estimate that the object traveled millions of years before entering the Solar System, ejected by gravitational interactions in its home star. The European Space Agency’s (ESA) Jupiter Icy Moons Explorer probe will observe the comet in February 2026, during peak activity, capturing data about its elongated and symmetrical structure, covered by an envelope of bright dust. Recent images show a shape that defies cometary standards, glowing intense blue as it reappears after perihelion, visible again in December 2025 at 270 million kilometres.meters from Earth. This unique opportunity allows us to study interstellar materials without direct collection, improving predictions for similar objects.

Challenges for international orbital measurements

The release of gas displaces the comet’s center of luminosity, generating errors in the predicted trajectories.

Observatories in Chile, Hawaii and Europe participate in simulations to standardize data. Experts adjust tracking algorithms in real time.

• Uncertainties reach 20% in objects with irregular jets.
• Hyperbolic models require constant corrections.
• Collaboration reduces deviations by up to 15% in simulations.

A workshop scheduled for November 10, 2025 brings together technicians to discuss specific adaptations to interstellar routes.

Global Coordinated Observation Campaign

The IAWN began exercises from November 27, 2025 to January 27, 2026, focusing on precise astrometry for comets such as 3I/ATLAS.

Integrated telescopes process real-time data between agencies. Tests simulate unexpected orbital deviations.

ESA entities and Asian observatories participate, improving rapid responses. The campaign aims to extract exact positions, even with non-gravitational accelerations.

Traject�ria and interstellar successors

Comet 3I/ATLAS follows ‘Oumuamua and 2I/Borisov as the third confirmed interstellar visitor, with a speed that confirms a hyperbolic route.

It heads towards Jupiter before leaving the Solar System in 2026, 240 million kilometers from Earth in December. Continuous monitoring tests early warning systems.

Technical partnerships for advanced studies

NASA sees the case as a chance to analyze interstellar materials, refining astrometric models with lessons from missions like DART.

Global partnerships strengthen detection of atypical objects. Collected data prepares agencies for complex scenarios by integrating dust and gas observations.