It seems we can't get off the planet fast enough. Two thirds of NASA's money is spent on manned space exploration, and that number will grow with the USA's decision to send a man to Mars in 2037. We've seen all there is to see on Earth, right? Wrong. The final place is here, under the surface of the sea.
Heading down into the ocean, human limits are quickly reached. At 200 metres, the water is as black as a moonless night. Most nuclear submarines (核潜艇) would implode (内爆) before they reach 1 km down. At 3 km—still less than the average depth of the ocean—there's a good chance that you'll discover a new species. The deepestdiving whales go no further. At the very bottom, about 11 km down, lies the Challenger Deep, the deepest part of the Mariana Trench in the Pacific Ocean. Eighteen humans have walked on the Moon, but only three have seen the Deep with their own eyes.
Yet things live down there. Big things. A very loud sound was once heard and scientists suggested that it was produced by an animal bigger than a blue whale, the largest creature known on the planet.
In the late 1990s, deepwater submarine was dropped in the Southern Ocean, and passing 4,000 metres, it discovered something huge passing under it. Surprised? Don't be. The ocean covers 70% of the planet's surface and we've studied less than 5% of it. We know more about the dark side of the Moon than about the bottom of the sea.
One reason that we explore space is to find evidence of other life forms. The search for life outside of Earth is important, but robots can look under the dry rocks of Mars better than humans. They're absolutely important for doing ocean research too, but they can't look under the sea. The cost of exploration is rising, but the results would benefit all our lives. Understanding the oceans will help us find new sources of food, drugs and energy.
Perhaps now it's time to begin a new period of sea exploration. Manned exploration of space is science fiction (科幻小说). The adventure of the deep sea is science fact.
