On this day 65 years ago, on January 14, 1960 (December 16, 1959 lunar calendar), humans dived to the bottom of the Mariana Trench for the first time. On January 14, 1960, Swiss physicist Jacques Picard and US Navy personnel Walsh, on the deep-sea diving vessel "Trieste", dived to the bottom of the Mariana Trench, reaching a depth of more than 11 kilometers. The mysterious Mariana Trench Jiaolong launched into the sea. The big-mouthed anglerfish living in the two or three kilometers of water in the Mariana Sea. The viper fish living in the Mariana Deep Sea use light-emitting organs to attract small fish. The bright red sun jellyfish can be seen at a depth of 5,000 meters in the Mariana Sea. Common sea fish and corals can be seen on the sea floor of two or three kilometers in the Mariana Sea. Walsh (left), Jacques and the "Trieste" deep-water probe "Deep Sea Challenger" are ready to go to sea. Japanese scientists explore the "Deep Sea 6500" manned deep-diving vehicle in the Mariana Trench. "I felt a strong sense of isolation, like being on the surface of a planet in outer space. "This is what American director Cameron said in an interview with reporters after returning from the Mariana Trench. Not long ago, China's" Jiaolong "deep-diving vehicle successfully broke through a depth of 7,000 meters in the Mariana Trench. The mysterious Mariana Trench has once again become the focus of the world's attention. There are very few seas in the world with a depth greater than 6,000 meters, accounting for only 1.2% of the total ocean area. In deep-sea waters, there are trenches in many places. Trenches are trenches located in the ocean. Generally, the two walls are steep, the shape is narrow and long, and the water depth is greater than 5,000 meters. Among all trenches, the Mariana Trench is the most famous because it is the deepest place in the world, with a maximum depth of 11,034 meters. The Mariana Trench is 2,550 kilometers long, with an average width of 70 kilometers, and most of the water depth is more than 8,000 meters. What does the Mariana Trench, which is more than 10,000 meters deep, look like? In January 1960, humans saw its true appearance for the first time. At that time, the famous Swiss deep-sea explorer Jacques Picard and US Navy Lieutenant Dorn Walsh piloted the "Trieste" deep-water probe for the first time in human history to dive to a depth of 10,000 meters in the Mariana Trench for scientific investigation. The main color they saw was black, and the appearance was like a desert. The water there was also very calm, and there were no more rough waves except for the currents stirred up by submersibles. Surprisingly, on the bottom of this desert, they found some deep-sea animals that humans have never seen before. Before this, the scientific community had determined that it was absolutely impossible for life to survive in such a deep sea. On March 26, 2012, Cameron piloted a unique deep-sea submarine alone and finally reached the bottom of the Mariana Trench at 10,898 meters. This is the second time that humans have reached the bottom of the Mariana Trench. Cameron became the third person to reach the 10,000-meter deep sea in history. Cameron's view of the Mariana Trench was similar to that of Jacques. When he returned for an interview, he said: "I just sat there, looking out the window, looking at the barren, alien-like sea floor, quietly admiring it. I experienced true loneliness, a feeling that overwhelmed everything, and I felt how small I was in this deep, vast, and inaccessible sea floor. "Mysterious Creatures of the Mariana Trench During Cameron's trip to the Mariana Deep Sea, the field of vision was mostly desolate, as if passing through a desert on land. In fact, there is no shortage of life in the deep sea" desert ". Divers have seen shrimp, squid, octopus, calamari, and large sea animals such as sperm whales at a depth of 2,000 to 3,000 meters in the Mariana Sea. In the depths of the water, schools of large-mouthed anglerfish were found. Even in the depths of 10,000 meters, Jacques and others found some flat-shaped fish and small red shrimp there. In the images sent back by the "Trench" machine in Japan in 1995, there were some white sea cucumber-like creatures squirming on the brown seafloor soil at a depth of 10,000 meters, and several small fish swimming next to them. For every 10 meters of water depth in the ocean, the water pressure increases by about 1 atmosphere. In the depths below 7,000 meters, the water pressure exceeds 700 atmospheres, which can crush ordinary family cars into pieces. So why are the animals in the Mariana Trench not squashed? This is because the body structure of deep-sea fish has undergone great changes. Their bones have become very thin and flexible, their muscle tissue has become particularly flexible, and their epidermis is very thin and transparent. In addition, because there is no light in the deep sea, some deep-sea animals have evolved light organs, some for their own lighting, and some are used to attract prey that can be swallowed. For example, the viperfish living in the Mariana deep sea has light organs that attract other small fish. In September 2010, Japanese scientists used the "Deep Sea 6500" manned submersible to discover a peculiar bivalve. This shellfish lives in the bottom of the sea at a depth of 5,620 meters near the "Chalinger" abyss in the Mariana Trench, and they absorb nutrients from the material in the mantle. This bivalve shell is a kind of white melon shell, 12 to 13 centimeters long. At those hydrothermal vents, the ejected mantle material reacts with the cold seawater to generate hydrogen sulfide with the smell of rotten eggs, and the swarms of white melon shells mainly live on this odor. In addition, carbonates produced by hydrothermal vents and sulfide bacteria near the vents are also sources of nutrients for bivalve shells. Another famous Mariana creature is the giant amoeba. In July 2011, a deep-sea probe in the United States discovered a ball-shaped animal with a diameter of 10 centimeters in the Selena Abyss at a depth of 10,641 meters in the Mariana Trench. After analysis, scientists found that this strange animal was actually a single-celled animal of the amoeba class, which was confirmed to be the largest single-celled animal in the world. Giant amoebas can not only adapt to dark, high pressure and cold seawater, but also have a strong tolerance for toxic heavy metals. What is terrifying is that they also actively "take drugs" and accumulate high concentrations of heavy metals such as lead, uranium and mercury in their bodies. The reason for the Mariana expedition craze Since the 19th century, explorers and scientists from all over the world have been diving into the Mariana Trench for exploration. From explorers' extreme attempts to scientists' exploration activities, why is the Mariana Trench so attractive? It turns out that deep-sea exploration is very challenging, it is more difficult than climbing mountains and going deep into space. At present, many mountaineers have successfully conquered the world's highest Mount Everest, and dozens of astronauts have reached hundreds of kilometers in space. However, only three people have successfully reached the 10,000-meter deep sea so far. Early explorations of the Mariana were to satisfy people's curiosity, and the exploration factor was more. Later, scientists realized that the deep sea, including the Mariana Sea, is a natural laboratory with excellent performance. "Exploring the Mariana Trench will help us better understand the earth and its biology, help discover new ecosystems, and understand new life forms," said Professor Doug Bartlett of the Scripps Institution of Oceanography at the University of California, San Diego. In addition to biologists, scientists from other disciplines are also enthusiastic about deep-sea research. For example, seismologists establish seismic observation networks on the seafloor to reduce the damage to coastal areas caused by deep-sea earthquakes and their tsunami. Even astrophysicists have to "plug in" the ocean. They have built an array of neutrino detectors in the deep sea, hoping to find neutrinos from space with the help of less disturbing deep-sea seawater. The pursuit of profit is also an important motivation for people to explore the Mariana Trench, because the deep sea is rich in natural resources. According to statistics, the final potential oil reserves in the world's deep-sea areas are as high as 100 billion barrels. In the past 10 years, 70% of the newly discovered oil and gas fields with proven reserves of more than 100 million tons are offshore, and more than half of them are located in the deep sea. A research team at the University of Tokyo in Japan found that the deep seabed silt, including the Mariana Sea, contains a large amount of rare earth resources, which can be mined about 800 times the amount of rare earth reserves on land. Two-thirds of the earth's surface is covered by oceans, with an average depth of up to 4,000 meters. They are rich in gold, copper, lead, zinc, nickel, manganese, cobalt, iron, and other minerals.