China's Tianwen-1 spacecraft, orbiting Mars, has captured close-up images of 3I/ATLAS, only the third confirmed interstellar object ever observed, following 'Oumuamua in 2017 and 2I/Borisov in 2019. The orbiter's High-Resolution Imaging Camera photographed the comet on October 3, 2025, from about 29 million kilometers away, revealing its tail and glowing coma.
The comet, roughly 5.6 km across, was moving at 58 km/s relative to the Sun and about 86 km/s relative to Tianwen-1, and appeared 10,000 to 100,000 times fainter than sunlit Martian terrain — a huge challenge for a camera built to photograph a bright planetary surface. European spacecraft Mars Express and the ExoMars Trace Gas Orbiter captured their own images of the comet on the same day.
3I/ATLAS was first detected on May 7, 2025, and Tianwen-1's observation marks one of the closest spacecraft encounters with the object since its discovery. The results add to a growing body of data on the visitor's composition, including confirmed water and volatile materials it releases as it approaches the inner solar system. China's upcoming Tianwen-2 mission and the European Space Agency's Comet Interceptor, due by 2029, aim to study future interstellar visitors up close.