Chinese probe on Mars captures unprecedented images of comet coming from another star system

Space exploration reached a historic milestone in October 2025, when the Chinese probe Tianwen-1, in full operation in the orbit of Marte, managed to obtain high-resolution images of comet 3I/ATLAS. The remarkable feat represents the first time an object of interstellar origin has been imaged from the orbit of another planet, establishing a monumental advance for planetary science and modern astronomy.

The recording was carried out at a considerable distance of approximately 30 million kilometers from the celestial body. The operation required extremely precise orbital maneuvers and detailed planning by Administração Espacial Nacional of China (CNSA), demonstrating the advanced technical capacity of the country’s space program.

The images captured are invaluable to the global scientific community, which now has crucial data to further study the composition and trajectory of objects that visit our Sistema Solar from other stars. The comet’s passage in the vicinity of Planeta Vermelho generated an international mobilization, with several space agencies redirecting their instruments to collect as much information as possible, transforming the event into a collaborative effort.

Visitor profile from another solar system

Comet 3I/ATLAS is the third object detected with a confirmed origin outside our Sistema Solar, following in the wake of ‘Oumuamua, observed in 2017, and 2I/Borisov, identified in 2019. With an estimated diameter of 5.6 kilometers and moving at an impressive speed of 58 kilometers per second, its analysis offers a unique opportunity to examine materials that formed in the protoplanetary disk of another star.

These objects function as true cosmic time capsules, carrying primordial information about their systems of origin and providing valuable clues about the formation and evolution of other planetary systems in Via Láctea. The scientific interest is immense, as they can reveal the chemical and physical diversity of other corners of the galaxy.

The technology behind the unprecedented capture

The Câmera of Imagem of Originalmente designed to map the surface of Marte with an exceptional level of detail, the mission engineering team demonstrated great versatility in adapting its use.

The equipment was reconfigured to track a small, extremely faint, fast-moving target against the dark background of deep space, a task for which it was not initially designed. Para To overcome the challenges posed by the comet’s high speed, which could easily result in blurry images without scientific utility, the CNSA team carried out exhaustive computer simulations.

The final strategy involved the use of extremely short exposure times combined with precise target tracking. Essa technique optimized light capture without sacrificing sharpness, allowing the raw data to be sent to the control center at Pequim, where a robust image processing system assembled the sequences, revealing the comet with unprecedented clarity.

What the images revealed about 3I/ATLAS

The photographs released by the Chinese space agency show with great clarity the rocky and frozen core of 3I/ATLAS, the heart of the comet. Este nucleus is surrounded by a coma, a diffuse cloud of gas and dust that forms when the heat generated by Sol sublimates the ice present on the comet’s surface, releasing matter into space.

The coma reached a diameter of thousands of kilometers, indicating very intense cometary activity. Preliminary analysis suggests the presence of water ice and carbon dioxide, as well as signs of carbon monoxide, whose composition points to its formation in an extremely cold region of its home star system.

The tail, formed by dust particles and ions pushed by the pressure of solar radiation, extended for approximately 56 thousand kilometers. The Esta structure, always aligned in the opposite direction to the Sol, is one of the most striking features of comets and provides information about the object’s interaction with the interplanetary environment.

The visual data, when combined with spectral analyzes from other instruments, allows scientists to build a more complete model of the comet’s chemical composition. Essa investigation helps compare “recipes” for forming planetary systems by seeing whether the building blocks of life, such as water and organic compounds, are common elsewhere in the galaxy.

A scientific collaboration on a planetary scale

A observação do 3I/ATLAS não foi um esforço exclusivo da China. Agência Espacial Europeia (ESA) also played an important role by using its Mars Express and ExoMars Trace Gas Orbiter probes to analyze gas emissions from the comet’s coma. Esses data provided a complementary perspective to the visual information obtained by Tianwen-1, allowing for a more in-depth chemical analysis of the atmosphere surrounding the comet’s nucleus and helping to identify the molecules that were being released by ice sublimation.

NASA also actively participated, directing Mars Reconnaissance Orbiter (MRO) to perform captures with its powerful HiRISE instrument. On the surface, rovers like Perseverance tried, albeit with great technical difficulty due to the distance and the Martian atmosphere, to detect the comet from the ground. Essa global observation campaign, uniting different agencies and instruments, maximized the scientific return of the event, transforming the 3I/ATLAS passage into an example of international cooperation in the exploration of the cosmos.

Detailed planning for a historical record

The Tianwen-1 mission team began planning to observe the comet in September 2025, as soon as orbital predictions became accurate enough to guarantee the success of the endeavor. The complex calculations took into account the high relative speed between the probe and the comet, as well as the object’s low brightness, which made it an extremely difficult target to capture. Todo the process was designed to ensure that the probe was in the correct orbital position and had its instruments properly calibrated at the exact moment of passage. The complexity of the maneuver, which involved adjusting the Tianwen-1’s orbit and precisely programming a sequence of commands, reinforces the China’s ability to execute highly technically difficult space operations autonomously, consolidating its position as one of the main powers in interplanetary exploration.

Context of the mission Tianwen-1 on Marte

Launched in July 2020, the Tianwen-1 mission is a milestone for the Chinese space program, being the country’s first mission, Marte, which included an orbiter, a lander and a rover, the Zhurong. The probe successfully entered Martian orbit in February 2021, and the rover landed on the vast plain of Utopia Planitia in May of the same year, operating for about an Earth year on the surface and expanding knowledge about the planet’s geological history.