Chinese probe Tianwen-1 records unprecedented images of the interstellar comet 3I/ATLAS from Mars

The Chinese probe Tianwen-1, on its mission in the orbit of Marte, achieved a remarkable feat by capturing unprecedented images of the interstellar comet 3I/ATLAS. The records, released by Administração Espacial Nacional of China (CNSA), show the object in motion, revealing details of its core and the cloud of gas and dust that surrounds it, known as a coma.

The observation occurred in July 2025, a strategic moment when the comet passed close to Sol and was temporarily out of reach of telescopes based on Terra. The maneuver’s success not only provided valuable data about a rare visitor from another star system, but also highlighted China’s growing technological capabilities in deep space exploration.

Comet 3I/ATLAS, discovered on July 1, 2025, is the third interstellar object confirmed to pass by our Sistema Solar, following in the footsteps of 1I/ʻOumuamua and 2I/Borisov. Sua’s high speed, approximately 58 km/s, and peculiar chemical composition quickly attracted the attention of the global scientific community, making each new observation extremely valuable.

A technical challenge in Martian orbit

Capturing the 3I/ATLAS images represented a significant technical challenge for the CNSA team. The High Resolution Camera (HiRIC) on board Tianwen-1 is designed to photograph the bright, well-lit surface of Marte. Adaptá to record a comet, an object between 10,000 and 100,000 times darker and fast-moving in deep space, required complex reprogramming and precise calculations.

Mission engineers performed detailed simulations to adjust the probe’s orientation and camera parameters, taking into account the comet’s exact trajectory and available solar illumination. The success of the operation demonstrated the versatility of the Tianwen-1 instruments and the control team’s ability to reconfigure a mission in real time to take advantage of a unique scientific opportunity, overcoming the original hardware limitations.

Interstellar Visitor Details

Comet 3I/ATLAS is considered a cosmic relic, with an age estimated at up to 10 billion years, possibly older than our own Sistema Solar. The Sua structure is composed of a rocky and icy core, which, when approaching the Sol, releases gases and dust to form a coma thousands of kilometers in diameter.

Observations confirmed that the comet’s trajectory was slightly altered during its passage through perihelion, the closest point to Sol. Essa change is a strong indication of mass loss, caused by a process of sublimation and release of gases, a phenomenon known as “de-gassing”.

This behavior provides important clues about the comet’s volatile composition, such as the presence of water ice, carbon monoxide and other substances that evaporate with heat. Detailed analysis of these gases can reveal the chemical conditions of the star system from which it originated.

Researchers are now dedicated to studying the images to map the structure of the coma and nucleus, seeking to better understand its origin and the journey that brought it to our planetary system. Cada detail can help build a more complete profile of these rare cosmic travelers.

The scientific importance of records

The observation of an interstellar object by a probe orbiting another planet is a milestone for modern astronomy. Cometas like 3I/ATLAS function as natural probes, bringing with them direct information about the composition and formation conditions of other stellar systems. By studying them, scientists can test and refine theories about how planets and planetary systems form elsewhere in the galaxy. The chemical composition of these objects, for example, can indicate whether the “ingredients” for life, such as water and organic compounds, are common in the universe. The Tianwen-1 mission, in orbit since February 2021, complements the work of other interplanetary missions, such as Mars Express from Agência Espacial Europeia (ESA), creating a network of space observatories that can be activated for events of opportunity like this. The data collected by the Chinese probe will help understand the comet’s interaction with the solar wind and the interplanetary environment, in addition to providing a privileged view of its morphology that would be impossible to obtain from Terra due to distance and atmospheric interference.

The Chinese space program in the spotlight

This achievement consolidates China’s position as a powerhouse in space exploration. The Tianwen-1 mission, whose name means “Questions to Céu”, was already a success as it placed an orbiter, a lander and a rover on Marte in its first attempt, something unprecedented.

The ability to redirect the probe for an unplanned and technically demanding observation demonstrates a high level of operational maturity and flexibility. Esse type of complex maneuver reinforces the reputation of CNSA and its body of engineers and scientists.

The successful observation of comet 3I/ATLAS positions China not only as a planet explorer, but also as a significant contributor to deep space science, actively participating in the frontier of astronomical knowledge alongside agencies such as NASA and ESA.

Additional observations and the future of the study

With the comet moving away from the brightness of Sol, telescopes on Terra and in space were able to resume observations, complementing the data obtained by Tianwen-1. The global astronomical community is mobilized to track 3I/ATLAS on its journey out of Sistema Solar.

There is also the expectation that other space missions will be able to observe it. ESA’s JUICE probe, on its way to Júpiter, may have the opportunity to capture new images, offering another perspective and contributing to a more complete and three-dimensional study of the object.

Data analysis continues

Currently, scientists at China and around the world are poring over the data sent back by Tianwen-1. Detailed analysis of the images and spectra obtained will allow us to define more precisely the composition of the comet, its rotation rate and the dynamics of its coma.

This information is crucial to confirm its interstellar origin and to compare it with other similar objects, helping to unravel the mysteries about the formation and diversity of planetary systems in Via Láctea. The results of this analysis promise significant advances in the field of planetary science.

Collaboration and mission planning

The success of the observation was the result of intense collaboration between CNSA’s flight engineering, mission operations and planetary scientists teams. The planning required perfect alignment between Tianwen-1’s orbit and the comet’s projected trajectory, a task that required weeks of preparation and millimeter orbital adjustments to ensure that the camera was pointed at the right place at the exact moment.