Interstellar comet 3I/ATLAS is photographed by the Chinese probe Tianwen-1 in an unprecedented feat since Mars

Space exploration reached a new milestone with the Chinese probe Tianwen-1, which made the first observation of an interstellar comet from the orbit of Marte. The object, identified as 3I/ATLAS, was recorded in a series of exclusive images during its passage through the Martian system in October 2025, at a distance of approximately 30 million kilometers. The Este event represents not only a technical triumph for the Administração Espacial Nacional of the China (CNSA), but also a unique opportunity for global planetary science.

The capture of the images was the result of a coordinated effort that tested the limits of technology and mission planning. The ability to repurpose an orbiter, designed primarily to study the surface of Marte, to track a small, fast, dimly lit object demonstrates an advanced level of operational versatility. The information collected by Tianwen-1 is crucial to understanding the composition and behavior of celestial bodies originating outside our Sistema Solar.

Comet 3I/ATLAS is the third confirmed interstellar visitor to be detected by astronomers, following in the footsteps of the enigmatic ‘Oumuamua in 2017 and the more conventional 2I/Borisov in 2019. Chile quickly caught the attention of the scientific community due to its hyperbolic trajectory, a clear indicator that its origin is far beyond the gravitational influence of Sol.

This achievement consolidates China’s position as a power in space exploration and reinforces the importance of international collaboration. Diversas other space agencies with active missions at

Technical details of the capture

Responsibility for capturing the images fell to the Tianwen-1’s high-resolution camera, known as HiRIC (High-Resolution Imaging Camera). Este instrument, originally designed to precisely map the topography and geology of the Martian surface, has been successfully adapted for a completely different task: astrometry of a fast-moving target in the vast blackness of deep space. The mission engineering team overcame significant challenges to carry out the observation.

To ensure that the 3I/ATLAS images were not blurred, engineers performed complex simulations to determine the ideal exposure time. Foi necessary to strike a delicate balance, using short exposures to freeze the comet’s motion without losing the faint signal reflected by its nucleus and coma. The raw data was transmitted to the control center at Pequim, where a specialized processing system assembled the 30-second sequences that revealed the object against a background of distant stars.

Logistical challenges of observation

Operating at a distance of 29 million kilometers from Marte presented a complex logistical puzzle for the mission team. Cada command sent from Terra took several minutes to reach the probe, requiring meticulous planning and impeccable execution. Ajustes Accurate targeting and maintaining the probe’s thermal stability were essential to ensuring the HiRIC camera could capture sharp images of the comet’s nucleus and coma.

An animation, carefully created from the sequential photographs, clearly illustrates the comet’s displacement against the fixed stellar backdrop. Estes visual records are extremely valuable, not only for their aesthetic appeal, but because they allow scientists to more accurately calculate the non-gravitational acceleration detected on the comet. Essa acceleration, a subtle deviation from the purely orbital trajectory, is caused by the ejection of gases and dust from the surface of the nucleus and provides important clues about the activity and internal composition of the celestial body.

Features of the comet revealed

The photographs released by CNSA reveal a rocky and icy core of 3I/ATLAS, surrounded by an extensive coma of gas and dust. The coma, which is the temporary atmosphere that forms when a comet approaches Sol, has reached a diameter of several thousand kilometers, a sign of intense cometary activity.

The object, with an estimated diameter of 5.6 kilometers, travels through space at an impressive speed of 58 kilometers per second. Sua tail, which was faint in early observations, expanded to about 56,000 kilometers in August 2025, pointing in the opposite direction to Sol, as expected.

Preliminary spectral analysis of the data indicates the presence of water ice and carbon dioxide, with fainter traces of carbon monoxide. Essa chemical composition suggests that the comet formed in a very cold protoplanetary disk, possibly in a region distant from its parent star in Via Láctea.

The data confirm a central core composed of rock and ice, which displays a reddish glow characteristic of organic dust, and a surrounding coma formed by the sublimation of volatile materials due to solar heat. The elongated tail, made up of ejected particles, and the anomalous acceleration complete the profile of this fascinating visitor.

In-depth preparation of Tianwen-1

Planning for this audacious observation began in September 2025, shortly after the comet’s trajectory was confirmed. The Tianwen-1 team relied on high-precision orbital predictions to calculate optimal observation windows, taking into account the comet’s speed, its low luminosity, and the probe’s position in its Martian orbit. Testes rigorous telemetry tests were carried out to ensure that the transmission of captured images occurred securely and without data loss. The focus on short exposures was a strategic decision to maximize the signal-to-noise ratio of the target, which was a considerable distance away at 18 million miles at the time of capture. Esta extension of the original mission not only tested the probe’s faint celestial body tracking capabilities, but also confirmed the effectiveness of detection protocols that will be used in future Chinese space missions. The operation also provided valuable experience in autonomous navigation, with the integration of subsystems optimizing real-time data processing.

Global contribution to data analysis

The 3I/ATLAS observation was not an isolated effort. Sondas from Agência Espacial Europeia (ESA), like Mars Express and ExoMars Trace Gas Orbiter (TGO), also recorded the comet in the same period. The data collected by European instruments complements the Chinese information, offering different geometric and spectral perspectives that enrich the analysis. NASA also played a key role, using the Mars Reconnaissance Orbiter (MRO) to capture ultra-high-resolution photographs with its HiRISE camera. On October 4, there were even attempts to capture images of the comet from the Martian surface, using the Curiosity and Perseverance rovers, although detecting such a faint object from the ground is extremely challenging.

The Hope probe, Emirados Árabes Unidos, and NASA’s MAVEN probe also contributed spectrometric data, monitoring the comet’s interaction with the space environment around Marte. Esses Collaborative efforts are essential to refine estimates about the orientation of the comet’s rotation axis and to accurately model the non-gravitational forces acting on it, painting a much more complete picture of this interstellar visitor. The nucleus, with its reddish glow, the gaseous coma and the particle tail were analyzed by multiple instruments, allowing a cross-study of the data.

Trajectory of the Tianwen-1 mission on Mars

Launched in July 2020, the Tianwen-1 mission marked a historic moment for Chinese space exploration by successfully entering the orbit of Marte in February 2021. The mission achieved another great feat with the successful landing of the Zhurong rover in May of the same year, on the vast plain of Utopia Planitia. During its year of operation on the surface, Zhurong collected soil samples, captured detailed geological images, and analyzed local mineral and atmospheric composition, providing a deeper understanding of the geological history of Marte and its past potential to harbor life. Enquanto this, the orbiter continues its work, mapping the planet with the HiRIC camera and currently focusing on studying polar ice and dust distribution, constantly expanding human knowledge about Planeta Vermelho.