Why does nasa do deep-sea research?

The ocean covers more than 70% of the earth's surface, but more than 80% of the ocean has not been explored by human beings. In fact, we often say that people's understanding of the surface of Mars and the moon is even far beyond our understanding of the depths of the ocean.

NASA has a deep-sea exploration program to make up for this deficiency. I hope that the exploration and discovery in the deepest part of the earth's oceans can help us see what the oceans of other planets in outer space may look like, and we can also try to break through the limits of human scientific and technological strength in the most extreme natural environment on earth. This deep-sea exploration is full of miracles and crises, and the risk of explosion disaster caused by huge water pressure is not small.

NASA hopes that the discovery of deep-sea exploration will help unlock some secrets of outer space, and at the same time, it can also test some equipment and experiments needed to explore other planets in the solar system.

The deepest part of the earth's ocean is strikingly similar to the environment in which NASA hopes to explore some planets in the solar system. Exploring the depths of the earth's oceans can even provide clues to tell scientists where to look for extraterrestrial life.

The deepest part of the earth's ocean is named after Hades, the god of hell in Greek mythology, and is called Hadar Belt. This ultra-abyss zone is really like the underworld imagined by human beings, and it is a forbidding area on the earth. It consists of unfathomable basins and trenches, and the deepest part can reach 1 1 km below the ocean surface. The total area of the seabed is equivalent to the whole of Australia. So far, only a handful of deep-sea submersibles dare to break into this dark abyss.

It is in this dark abyss that NASA scientists cooperated with woods hole oceanographic institution, Massachusetts, trying to explore and study the limits of life on earth. Even scientists use the same terminology as space exploration when exploring the abyss. For example, in recent years, marine biologists have sent many "landers" equipped with sensors and cameras to the crash site of the ocean abyss for measurement.

Engineers at NASA's Jet Propulsion Laboratory in Southern California are building a new type of automatic deep-sea exploration robot to map the deepest seabed in the abyss.

This deep-sea probe was named "orpheus". Orpheus is a hero in Greek mythology. According to legend, he traveled to and from the underworld in the abyss. Orpheus used a visual navigation technology similar to NASA's Perseverance Mars Rover, and used an ultra-sensitive camera to identify rocks, shells and other features on the seabed, thus drawing a three-dimensional map full of landmarks, or in other words, seabed markers. This technology can not only make the deep-sea exploration robot find its own path, but also identify the places that have been explored. This may also help orpheus to make new discoveries about creatures living in this harsh environment.

Tim Shank, a deep-sea biologist who led woods hole oceanographic institution's deep-sea exploration project, said, "orpheus is an attempt. If the exploration is successful, there will be no place in the ocean that humans can't reach. "

This is not the first time Shank has tried to go deep into the darkness of the abyss. In 20 14, nereus, the predecessor of orpheus, was sent to the Kemadek Trench in the northeast of New Zealand for exploration. However, the submersible probe exploded when it descended to 10 km underwater, probably because it could not bear the huge water pressure.

Schenk said, "12 hours later, we saw nereus become a small piece." He added that Nerus's failure made them rethink new ways to explore deep-sea areas. Orpheus is a redesigned deep-sea detector, which is about the size of a four-wheeled bicycle and weighs about 250kg. It is much lighter, smaller and cheaper than all previous underwater detectors. Lightness makes orpheus more flexible. It can enter trenches and underwater fountains in the depths of the sea that have never been explored before.

For a long time, marine biologists thought that there could be no life in the ultra-abyss, but in the first half of the 20th century, deep-sea submersibles began to venture into this sea area, only to find that there was the possibility of life in this restricted area.

Scientists at that time also believed that all living things in the ocean, without exception, were maintained by the food chain provided by photosynthesis. Plants, algae and some marine bacteria on the ocean surface convert the energy of the sun into sugar, which is stored in their organisms, and then eaten by herbivorous marine animals and then eaten by carnivorous marine animals, forming a marine food chain. Scientists are convinced that living things in the deep sea continue their lives by dead living things, including animal carcasses, feces, and "ocean snow" falling from the upper ocean, that is, organic debris falling like snowflakes in the deep sea.

At that time, scientists thought that there was not enough food to support any marine life in the deepest part of the ocean, where it was too dark and cold to exist at all.

However, it was not until 1977 that an American research team lowered a remotely controlled Alvin submersible to the bottom of the Pacific Ocean at a depth of 2,440 meters that human understanding of deep-sea creatures completely changed. The task of this submersible is to take pictures of this hot spring on the seabed. Because of submarine volcanic activity, heat is constantly coming out of the crater on the seabed.

Scientists were dumbfounded to find that there is a vibrant ecosystem around this submarine crater, full of marine life, such as translucent snails and crustaceans, as well as tiny flea-like crustaceans that have never been seen before.

Schenk said, "With this discovery, we have discovered a brand-new life form on the earth. These deep-sea animals don't rely on sunlight ... but on chemicals in the depths of the ocean. "

But scientists are also confused. How can species living at the bottom of the abyss endure huge water pressure and continue their lives?

Schenk said that in the ultra-deep area, "the water pressure reaches 0/5000 pounds per square inch/kloc." The pressure here is so great that every cell of the animal can be squeezed out. "

After 1977 witnessed this underwater wonder for the first time, scientists found that creatures living at this underwater depth can survive because their cells have been able to withstand huge water pressure. Living in the abyss, such as giant crustaceans and lionfish, there is a substance called piezoelectric body (from Greek, meaning pressure) in the body, which can prevent the cell membrane and protein from being crushed under extremely high pressure. Lysozyme will increase protein's space in the cell to counteract the weight of surrounding water and pressure.

It is found that creatures can not only survive in such a harsh environment, but also thrive, which raises an important question for biologists: can such creatures be found in the marine world of other planets outside our earth's territory?

Beneath the frozen crust of Jupiter's moon Europa is a liquid ocean, which is thought to be between 60 and 150 kilometers deep, and its water content is twice that of the earth's oceans. Sunlight can't penetrate Europa's thick ice shell, and there are criss-crossing cracks and broken marks on the ice. The pressure under Europa's ice crust is equivalent to the pressure in the ultra-deep area of the earth's ocean.

Schenk said. "Our earth also has its own Europa (the moon). I don't know how we can explore it on the earth's Europa unless we try it on the earth first. "

It is believed that robots that can detect the abyss of the earth's oceans can also do the same thing on the frozen moon (Europa of the earth) 628.3 million kilometers away.

Russell Smith, an engineer at NASA's Jet Propulsion Laboratory who participated in the construction of orpheus, said, "For us, the deep seabed of the earth is a good testing ground, and we can develop technology and successfully enter the marine world of these planets."

However, robots that can work in outer space or deep sea must be fully automatic. Smith said: "Robots must be able to make decisions." He pointed out that orpheus's goal is to be able to detect and classify environmental DNA and chemicals in seawater and retrieve samples from the seabed.

He said that it is a very difficult task to build a detection robot for ultra-deep areas.

Orpheus must endure enormous water pressure and extreme temperature. The water temperature in the ultra-abyss is only slightly above freezing point, but the temperature around the deep-sea hot springs can be as high as 370 degrees Celsius.

Smith said, "It is very difficult to develop a robot that can work in the ocean abyss. A fairly thick shell is needed to prevent electronic equipment from being crushed or soaked. " Part of orpheus's shell is made of synthetic foam, which is a buoyancy material composed of tiny glass balls placed in epoxy resin. The shell foam used by orpheus is the leftover material of James Cameron's Deep Sea Challenger. Cameron sank to the bottom of Mariana Trench in the western Pacific Ocean on the Deep Sea Challenger in 20 12.

As the deep sea is dark, orpheus is equipped with a huge spotlight. However, if the spotlight is always on and off, the battery of the robot will soon run out, leaving the robot trapped in the abyss of the ocean. Smith said that in order to save electricity, orpheus will switch to low-power mode when not taking pictures or sampling.

In 20 17, NASA launched a systematic underwater biogeochemical science and exploration simulation (seabed), which combined space and ocean exploration. So far, the program has completed two missions, using remote control submersible to detect hot spring vents on the bottom of the Pacific Ocean.

Scientists believe that the volcanic activities around the Luoxi submarine volcano (Lō `ihi) about 30 kilometers off the coast of Hawaii and the Golda Ridge about 120 kilometers off the coast of the United States at the junction of California and Oregon are very similar to those that may be found in the marine world under the ice of Europa and Saturn's moon Enceladus.

Darlene Lim, a geo-biologist who is in charge of NASA's undersea program and helps astronauts explore the moon and outer space, said, "The whole undersea project is based on our discovery that the characteristics of the deep-sea areas of the earth may be very similar to those of some planets, such as Enceladus."

Through these two deep-sea exploration operations planned by the seabed, scientists have learned more about the geological and chemical conditions of these two submarine craters and the surrounding ecology.

The deep sea area of the ocean not only has life, but also maintains a rich ecosystem, which may be unfamiliar to us. So far, it has been found that one of the creatures living in the deepest part of the ocean is a huge amphipod, which is more than 8 cm long. It was found in Richards Deep Sea, the deepest part of peru-chile trench, which is 8 kilometers deep. This deep-sea crustacean named Eurythenes atacamensis is a close relative of shrimp and a scavenger. It feeds on the remains of marine life floating in the upper ocean. It was discovered on 20 18 by Johanna Weston, a marine biologist from Newcastle University, and other researchers. It is reported that it is one of the richest creatures living in peru-chile trench.

In addition, there are at least three strange and quite fragile species in this deep sea area, such as lionfish and leggy. Each of these creatures can survive in extreme water pressure, low temperature and dark environment in the abyss.

Darlene Lin said, "These undersea hot spring vents are completely harmless. You must observe very carefully the temperature change of the interaction between hot water rising from the seabed and very cold seawater. Even this action is valuable in itself, because we may need to explore some marine worlds in the solar system. "

Although it may take decades to launch robotic probes into Europa and Enceladus, NASA scientists have applied their knowledge gained from deep-sea exploration to space missions.

By 2023, NASA will launch a robotic rover to search for water ice at the South Pole of the Moon. The mission named "Volatile Investing Polar Exploration Explorer (VIP)" will study the ice near Nobile, a lunar crater, hoping to develop lunar ice as rocket fuel or drinking water in the future. Although it does not operate underwater, the rover roaming the moon will face many technical challenges similar to underwater detection.

Darlene Lin is also the deputy chief scientist of the Viper Project. She said, "We will apply all the knowledge we have learned from the seabed to the Viper project."

The underwater project aims to ensure that scientists can achieve their research goals in a challenging environment, whether in communication or technology.

From an operational point of view, there are many similarities between ocean and space exploration. Robots are sent to these two fields to explore dangerous environments that humans can't reach, and teams of scientists support them remotely. In addition, the plan can also help astronauts lay the foundation for controlling robotic equipment at the lunar base in the future.

Subsea plans to explore the ocean with less than 10 scientists, but they will cooperate with more colleagues on the land team. As for the Viper project, a team operating a lunar rover almost at the same time on earth must quickly analyze the data and make decisions.

Zaramir Malec, a NASA social scientist who participated in these two projects, helped scientists prepare for exploration in extreme environments. She said that effective communication is crucial in these tasks.

Because of the complexity of deep-sea exploration, scientists have to adjust their plans and change their decisions at any time according to ocean conditions, weather and seawater salinity. Mir Malik said, "Your time is often less than expected. Deep-sea operations are extremely difficult because the deep-sea environment has high technical requirements. "

She said that in space missions, communication is extremely limited. In order to cope with the situation in outer space, Mir Malik restricted underwater scientists to communicate only once a day. She said, "Not a single mistake,