China’s Tianwen-1 spacecraft has photographed the interstellar object 3I/ATLAS as it passed near Mars, according to ScienceDaily and the China National Space Agency. The orbiter used its high-resolution camera to capture the comet from about 30 million kilometers away.
Tianwen-1 has been orbiting Mars for four years and eight months, making it one of the closest spacecraft to observe the object since it was discovered on May 7, 2025. The new images show a tail trailing behind the object and a cloud of gas and dust, or coma, around its nucleus.
Researchers also combined several images into an animation that shows the comet’s movement as it heads toward its closest approach to the Sun. The observations add to evidence that 3I/ATLAS contains water and other volatile materials that began escaping as it warmed in the inner solar system.
The imaging campaign was difficult because the object was both small and far away, and it was moving very quickly. According to the report, the comet was about 5.6 kilometers wide and traveling at around 58 kilometers per second, while its motion relative to Tianwen-1 reached roughly 86 kilometers per second.
The successful observation also offers a preview of the kind of work China hopes to do with Tianwen-2, which is expected to visit a near-Earth asteroid and later study a comet. Scientists say interstellar objects like 3I/ATLAS may help reveal how planetary systems form and what materials they contain.
