The earth has bred life for billions of years. We humans have only been on earth for millions of years. Although we humans appeared for a relatively short time, we humans are very special. Now we have entered a civilized society. , Has mastered many advanced technologies. Especially in the past 100 years, the blowout development of science and technology has allowed us to see the charm of science and technology. We humans can now walk out of the earth and into the deep space of the universe. However, when we went to space, we discovered that our current level of technology is still very limited, and may even make us feel a sense of frustration.
To the moon, which is about 380,000 kilometers away from our earth, the Apollo series of manned lunar spacecraft set off from the earth, landed on the surface of the moon, and then returned to the earth from the surface of the moon. The whole process takes about several days. If you go to a farther planet, it will take longer. For example, if you go to Mars, which is more than 55 million kilometers, the spacecraft will need to fly for nearly half a year. If you include the return time from Mars to Earth, it may take two years. With our current human technology level, how long will it take to get out of the solar system?
In 1977, we humans successively launched two unmanned spacecraft to start an interstellar flight journey, namely the Voyager 1 probe and the Voyager 2 probe. So far, the two unmanned spacecraft have been galloping in outer space for more than 40 years, and are very far away from our earth. Among them, the distance between the Voyager 1 probe and our earth has reached 150 astronomical units (1 astronomical unit is between the earth and the earth). The average distance of the sun is about 150 million kilometers), so the distance between the Voyager 1 probe and our earth has reached 22.5 billion kilometers.
What is the concept of this distance? From our earth to the Voyager 1 detector, it takes 20 hours and 43 minutes for the signal to be received by the detector. When the detector receives the signal, it immediately responds to us, and the reply takes another 20 hours and 43 minutes. To be received by us. Therefore, the current Voyager 1 probe is very far away from us.
On February 14, 1990, the Voyager 1 probe completed its first mission. At that time, it had reached 6.4 billion kilometers away from us. NASA issued an order to look back at the solar system and photographed a family portrait of the solar system. Due to the very long distance, it is no longer possible to see the appearance of the earth, except that there is a “dark blue dot” in the dark starry sky. In the photos sent back from the Voyager 1 probe, our earth only occupies 0.12 pixels of the entire photo, and our earth home is very small.
However, compared with the vast universe, the distance between the Voyager 1 probe and our earth appears very close. Take our solar system as an example. At present, the Voyager 1 probe has not completely flew out of the solar system because the diameter of our solar system is far more than 1 light-year. There is not only the Kuiper belt outside the solar system, but also a very large Oort. nebula. According to the current flight speed and direction, some scientists have calculated that the Voyager 1 probe will need to continue to fly for 40,000 years before it can reach the next star system. Obviously, this kind of flight time cannot be accepted by us. Does our technology seem insignificant in the face of the vast universe?
One reason for our exploration of the universe is to find other habitable planets in order to realize interstellar migration in the future. Judging from the current exploration situation, there is no planet in our solar system that is completely suitable for our humans to live in. We can find potential in the future. The habitable planets are probably some extrasolar planets that are very far away from us. It is unrealistic for us to get out of the solar system in a short time. Are we really “trapped” on the earth?
It may seem like this, but the actual situation may not be so pessimistic. We will not talk about habitable exoplanets for the time being. In fact, there are some planets in our solar system that can become our “second home”, such as Mars. Of course, the current Mars is not suitable for us to live directly, so before we emigrate to Mars, we need to modify Mars to increase the temperature of the surface of Mars, improve the atmospheric environment of Mars, and melt the water ice material of Mars, using liquid water. Form exists. This seems incredible, but it is possible. Some scientists said that the entire transformation process of Mars may take about 200-300 years. After the transformation of Mars is completed, immigration to Mars may be possible, and we humans can get out of the earth. Then with the help of Mars as a springboard, we humans may go farther into the depths of the universe.