Far beneath the surface of the western Pacific Ocean, south of Japan and east of the Philippines archipelago, lies the deepest known point on Earth: the Mariana Trench.

This underwater chasm is nearly 11 km deep – around two kilometres deeper than Mount Everest is tall – 69 km wide and extends for 2,540 km. The nearest land is the Mariana Islands, 200 km to the west.

Down here, the pressure is crushing – just imagine having an elephant pressing on your fingertip and that same force exerted on your entire body. Moreover, the Mariana Trench is an icy, pitch-black world unlike anything on the surface. It’s a place where light never reaches, temperatures hover just above freezing, and the weight of the ocean above is almost unimaginable.

Since the first descent by Swiss-American explorers in 1960, the trench has drawn the attention of scientists worldwide. But in recent years, no country has pursued its secrets more eagerly than China as it would be “the perfect playground” for their future ambitions in space-related research. Its rapid expansion in exploration efforts in the trench have sparked questions worldwide.

China’s deep-sea dragon

In 2020, China launched Fendouzhe (which means “striver” in Mandarin), a Chinese-made submersible designed for full-ocean-depth exploration. It became widely known for diving to 10,909 m in the Mariana Trench, breaking China’s own previous record and marking one of the deepest ever manned dives.

Xu Xun, a researcher involved in the Mariana Trench studies, has suggested these findings could help scientists understand how alien life might survive in harsh extraterrestrial conditions.

Resources for car manufacturing

The trench also contains large deposits of minerals, metals and rare earth elements. Many of its polymetallic nodules – particularly manganese, nickel, and cobalt – have higher metal concentrations than land-based deposits, making them particularly valuable. These materials are the foundation of modern technologies, especially electric vehicle batteries, which are critical for large car brands in China such as BYD, Changan and Geely.

However, global experts have argued against China’s use of these resources. Deep sea mining risks permanently damaging the trench’s ecosystem, which may take millions of years to recover – if recovery is possible at all.

For these reasons, the Chinese government is still finding methods to extract all these materials without harming the trench.

Deep-sea space station

China has also proposed building a “deep-sea space station” – a permanent underwater base for long-term research – 1,800 metres below the surface of the South China Sea. It would be able to accommodate six scientists for a month at a time, who would be able to live and work underwater.

The facility would be used for monitoring volcanic activity and cold seeps, study deep-sea organisms for space biology research, and to act as a training ground for astronauts in high-pressure environments. It is expected to be completed by 2030.

American researchers first discovered cold seeps in the Gulf of Mexico in 1984. Fluids rich in chemicals such as methane and hydrogen sulfide escape from crevices in the seafloor, creating unique ecosystems that are not dependent on sunlight. Animals that depend on cold seeps include giant tubeworms and sea cucumbers.

China isn’t just exploring the Mariana Trench – it’s claiming the underground trench as a lab for future discoveries in space. From discovering foreign microbes to metal nodules that could power the next generation of electric cars, China’s deep-sea missions are bold, risky and revolutionary. But with that ambition comes a massive responsibility.

The Mariana Trench could become the perfect playground for China’s future aspirations in space. However, if innovation is not balanced with protection, humanity risks losing one of Earth’s most mysterious ecosystems before it is fully understood.