Chinese probe Tianwen-1 captures unprecedented images of the interstellar comet 3I/ATLAS in orbit around Mars

Space exploration reached a new historic milestone in October 2025, when the Chinese probe Tianwen-1, operating in the orbit of Marte, managed to photograph comet 3I/ATLAS in high resolution. Este event represents the first time that an object of interstellar origin is observed and recorded in detail from the orbit of another planet, consolidating a significant advance for planetary science and modern astronomy.

The recording was carried out at an approximate distance of 30 million kilometers from the celestial body, a feat that required highly precise maneuvers and meticulous planning on the part of Administração Espacial Nacional of China (CNSA). The images obtained provide crucial data for the global scientific community, which can now study in more depth the composition and trajectory of visitors from outside our Sistema Solar.

The passage of comet 3I/ATLAS in the vicinity of Planeta Vermelho mobilized several space agencies, which directed their equipment to collect as much information as possible. International collaboration was essential to cross-reference data and obtain a more complete understanding of the nature of this rare cosmic object, transforming the observation into a global effort.

Origin and characteristics of the interstellar visitor

Comet 3I/ATLAS is the third object with a confirmed origin outside our Sistema Solar to be detected by astronomers, following the passes of ‘Oumuamua in 2017 and 2I/Borisov in 2019. Sua official designation was granted following its discovery in 2024 by the ATLAS astronomical survey system (Asteroid Last Alert System), operated from the Havaí and the Chile. The main evidence of its extrasolar origin is its trajectory, described as a sharp hyperbolic orbit, which indicates that it has enough speed to escape the gravitational attraction of Sol and is just passing through our system. About 5.6 kilometers in diameter and traveling at a speed of 58 kilometers per second, its analysis offers a unique opportunity to study materials formed in the protoplanetary disk of another star, providing valuable clues about the formation of other planetary systems in Via Láctea.

The technical prowess of the HiRIC camera

The central instrument for the success of the observation was the high-resolution camera HiRIC (High Resolution Imaging Camera), on board the Tianwen-1. Originalmente designed with the aim of mapping the surface of The complexity of the task required a complete recalibration of the probe’s targeting and tracking systems.

To overcome the challenge of capturing such a fast-moving object without generating blurry images, extensive simulations were carried out on land. The strategy adopted consisted of using extremely short exposure times, optimizing light capture and ensuring the sharpness necessary for scientific analysis. The raw data was transmitted to the control center at Pequim, where a specialized processing system assembled the image sequences, revealing the comet with remarkable clarity and precision.

Preliminary analysis of captured images

The photographs released by CNSA clearly show the rocky and frozen core of 3I/ATLAS. The Este nucleus is surrounded by a coma, a cloud of gas and dust that forms when the heat from the Sol sublimates the ice on the comet’s surface.

The coma reached a diameter of thousands of kilometers, an indication of very intense cometary activity for an object of its size. The tail, formed by particles ejected by solar radiation pressure, extended for approximately 56,000 kilometers.

Preliminary spectral analyses, based on the data collected, suggest the presence of water ice and carbon dioxide. Também weaker signals of carbon monoxide were detected, a composition that points to a formation in a very cold region of its home star system.

The reddish glow observed in the core is attributed to the presence of dust rich in organic compounds. Além In addition, scientists analyze a non-gravitational acceleration, a slight deviation in the trajectory that indicates additional forces caused by the ejection of gases from its surface.

Scientific effort unites space agencies

The passage of 3I/ATLAS through Marte was not observed only through China. Agência Espacial Europeia (ESA) used its Mars Express and ExoMars Trace Gas Orbiter probes to analyze gaseous emissions from the comet’s coma, providing a complementary perspective to the Chinese data.

NASA also actively participated in the effort, directing Mars Reconnaissance Orbiter (MRO) to capture images with its powerful HiRISE instrument. On the surface, rovers like Perseverance tried to detect the comet from the Martian soil, while the MAVEN probe collected spectrometric data, enriching the set of information.

Context of the successful mission Tianwen-1

Launched in July 2020, the Tianwen-1 mission represents a milestone for the Chinese space program, being the country’s first mission, Marte. The probe successfully entered Martian orbit in February 2021, carrying an orbiter, a lander and the Zhurong rover.

In May 2021, the Zhurong rover landed on the vast plain of Utopia Planitia, where it operated for approximately one Earth year. Durante its mission on the surface, the rover collected geological data, analyzed the composition of the soil and atmosphere and sent back detailed images of the terrain, while the orbiter continues its work mapping the planet.

Next steps for the China space program

The successful 3I/ATLAS observations serve as an important validation of the technologies and methods that will be employed in future Chinese missions. The experience gained strengthens the Sistema Solar smaller bodies exploration program, one of the CNSA’s focuses for the next decade.

The Tianwen-2 mission, launched in May 2025, is the next big step. Seu objective is to collect samples from an asteroid close to Terra and, subsequently, study a comet from the main belt.

The 3I/ATLAS tracking confirms China’s ability to conduct complex operations in deep space, paving the way for even more ambitious explorations in the near future.

Thorough planning ensured success

The Tianwen-1 mission team began planning to observe the comet in September 2025, as soon as orbital predictions became accurate enough. The calculations took into account the object’s high speed and low luminosity to determine the ideal observation windows, ensuring that the probe was in the correct position and the instruments were properly calibrated for the historical record.