China's Tianwen 3 robotic mission is expected to become the world's first Mars sample return mission, with the search for traces of Martian life as its top scientific goal, according to the mission's chief scientist.

Hou Zengqian, an academician of the Chinese Academy of Sciences, stated on Thursday in Hefei, Anhui province, that Mars is one of the terrestrial planets in our solar system similar to Earth.

"Ample evidence has shown that early Mars had liquid water, a denser atmosphere, and a global magnetic field — key conditions for forming a habitable environment. That is why the mission takes searching for potential signs of past Martian life as its primary objective. Through detailed analysis of returned samples, scientists hope to find reliable bio-signatures," said Hou, who is also the director of the State Key Laboratory of Deep Earth and Mineral Exploration under the Chinese Academy of Geological Sciences.

He said that solid evidence of past Martian life, if found, would have profound implications for answering the fundamental question of whether life has ever existed beyond Earth. The mission will also study Mars' habitability, geological and internal structure, and atmospheric evolution, according to the scientist.

"These topics are closely linked, as life relies on habitable environments, which are shaped by the Red Planet's long-term geological and climatic changes," he explained.

Hou made the remarks on the sidelines of the International Deep Space Exploration Conference 2026, which opened on Thursday in Hefei. According to the China National Space Administration, the Tianwen 3 probe will have five components — a lander, an ascender, a service capsule, an orbiter, and a reentry module — and will be launched around 2028 on two Long March 5 heavy-lift carrier rockets from the Wenchang Space Launch Center in Hainan province.

If everything goes according to plan, the mission will collect samples from the Martian surface and then send them back to Earth around 2031, becoming the first to return the Red Planet's substances to Earth. To prepare for the return of the precious Martian samples, Hou said, China will build the world's first planetary protection laboratory to prevent both forward contamination of Mars by Earth microbes and backward contamination of Earth by returned samples, while keeping Martian samples free of terrestrial pollution.