Interstellar comet 3I/ATLAS mobilizes UN global observation campaign for two months

Rede Internacional of Alerta of Esta initiative, activated on November 27, 2025, in Genebra, Suíça, aims to significantly improve tracking techniques for celestial objects, especially those of a diffuse nature, during the comet’s passage through Sistema Solar.

Experts from different nations actively participate in this coordinated action, scheduled to last two months, extending until January 27, 2026. The main objective is to collect precise data that allows the refinement of orbital models and measurement methodologies for celestial bodies with less defined characteristics than point asteroids.

Comet 3I/ATLAS, discovered in July 2025 by the ATLAS system in Chile, does not pose any threat of collision with Terra. Sua already confirmed hyperbolic trajectory indicates an origin outside the limits of our Sistema Solar, which makes it a unique object of study for the international scientific community.

Discovery and first analyzes of the comet

Comet 3I/ATLAS was initially detected as a faint spot in images captured by the ATLAS telescope, located in the Atacama desert, at Chile. Astrônomos identified its fuzzy appearance shortly after the first detection, marking the beginning of an intense period of observation.

Preliminary observations carried out on July 2, 2025, by telescopes such as the Lowell at Arizona and the Canada-France-Hawaii at Mauna Kea, revealed a marginal coma and an elongation of three seconds of arc. Esses first records were crucial to confirm the object’s cometary activity.

Subsequent surveys, including those of the Nordic Optical Telescope at Ilhas Canárias and the Two-Meter Twin Telescope at the Observatório of Tais data indicates the continuous release of gases and dust under solar radiation.

The initial discovery occurred on July 1, 2025, by ATLAS, with activity confirmed on July 2, when the coma and tail were detected. The comet’s perihelion was on October 29, 2025, at 1.35 astronomical units from Sol.

IAWN Global Monitoring and Engagement

The IAWN monitoring campaign, which began on November 27, 2025, establishes an intense period of calibration of orbital models by telescopes spread across multiple continents. The precision required for diffuse objects like 3I/ATLAS is significantly greater than that required for asteroids, requiring delicate adjustments to the tracking algorithms.

Renowned space agencies, including NASA and ESA, are among the active participants in this initiative. In November, spacecraft orbiting Marte captured images of the comet from a distance of 18 million miles, revealing a bright coma, an unusual tail and a conical shape with a green core shrouded in luminous haze.

Contribution from space agencies and observatories

NASA played a key role in providing detailed images of comet 3I/ATLAS, taken by three probes at Marte during approach in November 2025. The captures, taken from 29 million kilometers, confirmed the typical cometary features, with the Amit Kshatriya director stating that the object exhibits common characteristics, with no signs of atypical origins.

Agência Espacial Europeia (ESA) has planned observations with the Juice probe, between November 2 and 23, 2025. The data collected by this mission is expected to reach Terra in February 2026, focusing on post-perihelion activity, and the instrument will analyze the gas composition and ejected dust.

In Brasil, Observatório Nacional monitors orbital variations that can be caused by gas jets. On October 21, 2025, a call was made for additional measurements to characterize possible deviations, although astronomer Jorge Márcio Carvano emphasized the absence of significant anomalies.

Amateur participation and data collected

Amateur astronomers have contributed detailed records as of November 2025, complementing professional observations. Imagens of

Professionals used Deep Random Survey on Chile to measure tail elongation in July, and Instituto of Astrofísica of Canarias confirmed the activity on Observatório of Esses Combined efforts are essential to building a comprehensive global database on 3I/ATLAS.

Hyperbolic trajectory and celestial interactions

Comet 3I/ATLAS follows a hyperbolic orbit, indicating its entry into Sistema Solar from the southern celestial hemisphere. Descoberto five astronomical units from Sol, it reached its perihelion on October 29, 2025, at a distance of 1.35 astronomical units. The closest approach to Terra is scheduled for December 19, 2025, at 1.8 astronomical units, without any risk of collision. The pass by Marte in November allowed probes to capture images from 18 million miles away, making it easier to analyze its coma and tail. In March 2026, the comet will approach Júpiter, on March 16, and the gas giant’s gravity could divert its route, propelling it towards the constellation of Gêmeos. Simulações Indian women predict a subtle change, projecting a 100-year journey through intergalactic space. The Juno probe will observe this encounter, collecting crucial data on orbital dynamics, while ESA, with the Juice probe, will contribute spectroscopy, testing gravitational models for interstellar objects.

Improving the astrometry of diffuse objects

The 3I/ATLAS observation campaign is improving position measurements for diffuse comets. Telescópios are adjusting their algorithms to deal with blurred contours, resulting in an accuracy improvement of about 20% for similar objects. The data collected in November 2025 is essential for calibrating systems against brightness variations.

The international collaboration involves a network of 50 observatories working together, with IAWN coordinating the daily sending of coordinates. NASA also integrates TESS for early detection, with data backdated to May 2025.

Characteristics and spectral composition of 3I/ATLAS

Preliminary spectral analyzes reveal that the 3I/ATLAS coma contains organics and metals. The reddish glow observed indicates the presence of carbonaceous dust, a characteristic similar to that of comet 2I/Borisov. The detection of nickel in vapor suggests a metal-rich nucleus, which is relatively unusual for comets.