The Chinese spacecraft Tianwen-1, orbiting Mars, photographed the interstellar comet 3I/ATLAS. Its images were published by the China National Space Administration (CNSA).
On October 3, interstellar comet 3I/ATLAS flew past Mars at a distance of 30 million km. Space agencies took advantage of this opportunity to study the visitor from another star system. The comet was photographed by the European TGO spacecraft and the Perseverance rover, among others.
As it turned out, a Chinese spacecraft also took part in the 3I/ATLAS shoot. Preparations for it began back in September. It was a very difficult task due to the enormous distance to the object, its high heliocentric velocity (approximately 58 km/s), the orbital motion of Tianwen-1, and the relatively small size of the comet. Another important factor was that the Tianwen-1 camera was designed to photograph the bright surface of Mars, while 3I/ATLAS was 10,000–100,000 times dimmer than its standard target.
Despite all these difficulties, the mission specialists managed to correctly determine the order of use of the Tianwen-1 camera and calculate the shooting parameters, which allowed the task to be successfully completed. Due to the small size of the comet, its nucleus is indistinguishable in the image—we see the coma surrounding it (a cloud of gas and dust) with a diameter of several thousand kilometers. Chinese researchers also created an animation from a series of 30-second frames illustrating the movement of the object.
The CNSA stated that imaging the comet was an important addition to the Tianwen-1 mission. Observing such a dim object provided an opportunity to conduct useful technical tests and gain experience for the Tianwen-2 mission. It was launched in May 2025 with the aim of delivering a soil sample from a quasi-moon of Earth called Kamo`oalewa to Earth.
Earlier, we reported on how an interstellar comet unexpectedly changed color.
According to CNSA
