Tìm Kiếm Thế Giới Khả Sinh | Thiên Hà TV

The universe contains billions of galaxies, each galaxy contains billions of stars, and many stars have planets orbiting around them. So, how do we find life in such a vast place? It's like a gold mine at the bottom of the sea. We want to focus on finding planets that are likely to have high life, what we call the planet of birth. So, what do those planets look like? To answer, we don't look outside the universe, we look at this planet, the Earth. Because this is the only planet that we know can live. When we look at the Earth from the universe, we see a green world full of water. It's not a coincidence that three-quarters of the Earth's surface is covered by the ocean, because of the physical and chemical properties that only water has. Water is necessary for all life, and that's why we pay special attention to planets with a lot of water. Fortunately, water is very common in the universe, but life needs water in the form of water, not ice or air, and water in the form of water is less common. For a planet to have water in the form of water on the surface, there are three important things. First, that planet needs to be large enough so that the gravitational force can prevent water particles from flying into space. For example, Mars is smaller than Earth, so it has a smaller gravitational force, and that's why Mars' atmosphere is very thin, and there is no ocean on the surface. Second, that planet needs to have an atmosphere. Why? Because if it doesn't, the planet will be in the air, and the water in the ocean is not stable in the air. For example, Mars does not have an atmosphere, so when we pour a little water on Mars, it will boil into air or solidify into ice. Without atmospheric pressure, water in the ocean cannot exist. Third, that planet needs to have a suitable distance from its star. If too close, the temperature on the surface will exceed the boiling temperature of the water, and the ocean will turn into water vapor. If too far, the surface temperature will be lower than the freezing temperature of the water, causing the oceans to freeze into ice. Whether it's fire or ice, the life we know will not exist. Think about the planet, the place in the middle of the ocean, like a belt around its star. We call that belt the life zone. So, when we look for the planet, we will look for the life zone around the stars. It is the most suitable area to find a planet that lives on Earth. Although the life zone is a good place to find planets with life, there are still some difficulties. First, a planet may not be able to live just because it is in the life zone. Let's take a look at the stars in the solar system. If you are an astronaut, you will see that the stars have life, the right size, have the right atmosphere, and are in the life zone of the solar system. They can look at the stars and the Earth as twins, but the stars cannot have life, at least on its surface. It's not the life we used to know. It's through heat, and the star's atmosphere is full of CO2, an important greenhouse gas. In fact, most of the star's atmosphere is CO2. It is nearly 100 times thicker than our atmosphere. As a result, the temperature on the star is so hot that it can melt, and this planet is as dry as a desert. So a planet with the right size and distance is just the beginning. We need to know its component of the atmosphere. The second difficulty appears when we take a closer look at the Earth. For the past 30 years, we have found organisms that live in hot environments. They live in deep-water glaciers several kilometers below the ground, in boiling water under the sea, in the acidic water of hot springs, in high-pressure water in the sky. These organisms are not rare. Some scientists estimate that the amount of organisms living deep in the Earth is equal to the amount of all organisms living on the surface of the Earth. These submerged organisms do not need the ocean or the sun. This shows that planets like the Earth may just be the surface of the galaxy of cosmological organisms. Maybe life still exists in the submersible layer under the surface of the galaxy, because organisms can live on the Europa of the galaxy, where the deep-water ocean lies under the hard ice surface. Another ocean lies under the surface of the satellite Enceladus of Saturn, which is the source of hot springs flowing into the universe. Does this hot spring contain organisms? Can we fly there to find out? Is there anything about life that we don't know? Using a substance different from water, maybe we are the strange creatures living in a harsh and unusual place. Maybe the area of ​​real life is too large, there are billions of pines under the ocean. Maybe on the surface of the Earth, the Earth is just one of many worlds. The only way to find out is to go out there and explore. Deep in our solar system, a new universe is gradually opening up. Under the thick layer of the Europa satellite, in the bubbles from Enceladus, and in the methane lakes from Titan, organisms are looking for life on Earth. They study these three satellites carefully, because they are all ocean worlds, an environment rich in oxygen, and oxygen helps form life. Creatures have to be able to reproduce, reproduce and find food among other species. All of the above activities require complex molecular structures from basic components. Substances such as water allow the substances to remain in a floating state instead of sinking due to attractive force. This helps them interact frequently in space and in suitable conditions. Chemical reactions will occur, leading to the formation of living substances. That alone is not enough. Small but complex organisms that we know are sensitive to too hot or too cold temperatures will not be able to produce reactions. Fresh water has the advantage of having a very stable temperature, which means it can isolate the molecules from major changes in temperature. On Earth, along with other conditions in the water environment, it may have contributed to the presence of life billions of years ago. The same thing can happen to other planets in the solar system, such as these three moons. Europa, the moon of Jupiter, is the most attractive ocean. Under a layer thicker than the Everest, there is an ocean up to 100 km deep. Biologists believe that this deep ocean can contain life. Thanks to Galileo, we can deduce that it has a similar amount of salt compared to some lakes on Earth. But now, most of its elements are still a mystery. Just like Jupiter, Jupiter also has satellites suitable for life. For example, Enceladus is a small balloon that can fit in the Halong Bay area. Similarly, Europa, a large ocean may also be hidden under its layer of ice. But Enceladus also has water channels and small grains of ice in space. Biologists are curious if these water channels are connected to the ocean below. They hope to send a probe to see if the air flow from the water channels contains substances that support life from this deep ocean. Although substances are the most well-known for nurturing life, water is not a necessary environment. For example, Titan, the largest satellite of Jupiter, has a lot of gas, methane gas, and other chemical elements. Clouds and rain on the surface of Titan make lakes and oceans full of methane. This special chemical compound does not have good support like water, but combined with a large amount of organic matter falling from the rain, these methane clouds are able to support strange living things. So what indicates that there is life here and elsewhere? If there is life, biologists estimate that they exist at the molecular level, compared to the microorganisms we have on Earth. This makes it difficult for direct observation from afar, so biologists are looking for the so-called biology. It can be cells, fossils, or minerals left by organisms. And finding any biology is also a challenge for many reasons. One of the most important things is to ensure that the worms are well fed. If not, we can accidentally pollute those oceans with the bacteria of the Earth, which can destroy life on the planet. Titan, Enceladus, and Europa are just three of the many oceans that we can explore. We also know many other places in the solar system, including the satellites of the planets Callisto and Ganymede, the Triton of the Milky Way, and the Gemini, if there are many potentials for life in our tiny solar system. So, what about the rest of the universe? Can it hold any more unimaginable secrets? Thank you for watching! See you in the next video!