This paper takes part in the series essay competition of “great science” of Recordunkown.
In 1957, the first man-made satellite was launched into space. From this moment on, it marks the beginning of the pace of human development into space. When human beings really walk out of the earth, they will know how vast the universe is, and the earth is as small as dust in front of the universe.
When mankind walked out of the earth and saw the vast universe, an eternal question appeared: does alien civilization exist? I believe that everyone is very curious about alien civilization and wants to know what it looks like? For scientists, the exploration of extraterrestrial civilization is even more enthusiastic, so soon after human beings came out of the earth, they started the extraterrestrial civilization exploration plan.
There are two ways to explore extraterrestrial civilization. One is to rely on astronomical telescopes to observe and explore, hoping to find some clues of extraterrestrial civilization. The other is to send spacecraft to explore. On September 5, 1977, the famous space probe Voyager 1 was launched.
Voyager one’s mission is to move forward to the vast starry sky, go out of the solar system and explore the existence of alien civilization. Now it has been flying for 43 years, with a distance of more than 20 billion kilometers. It has stepped out of the top of the heliosphere and entered interstellar space. Many people may have such a question: isn’t it true that there are many asteroids in the solar system? Why hasn’t Voyager one hit an asteroid in 43 years? Is it very lucky?
I believe many people know that the number of asteroids in the solar system is too large to be estimated. Since this year, there have been several asteroids hitting the earth, and on April 29, a relatively large asteroid will also fly over the earth. It can be seen that the number of small rows in the solar system is indeed very large, and it is true.
According to the observation of scientists, there are two major asteroid belts in the solar system. One is located between Jupiter and Mars, where there are more than a million asteroids. Another asteroid belt is the Kuiper belt at the edge of the solar system, which encircles the solar system and surrounds the eight planets. The number of asteroids in the Kuiper belt is too large to be estimated.
Voyager 1 must cross these two asteroid belts to fly out of the solar system and into interstellar space. Some people may say that we can avoid the asteroid belt between Jupiter and Mars. Why go there? In fact, Voyager one has to go to Jupiter, because the speed of the spacecraft itself is very slow. To get faster speed, we must use the gravitational catapult effect, that is, to use Jupiter’s strong gravity to accelerate the spacecraft.
Only through the gravitational acceleration of Jupiter can Voyager 1 speed up significantly, go to the edge of the solar system faster, and get out of the solar system. If so, why didn’t a large number of asteroids in the asteroid belt do harm to Voyager 1? As we all know, asteroids are not stationary. They have super fast speed. Once Voyager 1 is touched by an asteroid, the spacecraft will be finished.
The reason why voyager-1 didn’t encounter an asteroid is not to say how lucky it is. The main reason is that the density of asteroids is too low. Maybe many of our knowledge of the asteroid belt is based on the images taken by the detectors. In the images, we can see dense asteroids, one by one, without too much space.
If you look at the density of asteroids in the picture, it’s hard for any spacecraft to cross. But the real asteroid belt is not like this. The detector takes pictures at a distance, which is a miniature of the long-distance asteroid belt. So what we see is a very dense distribution of asteroids.
However, the real distribution of asteroids is very broad. Relevant data show that the asteroid belt occupies a space area about 2.17 to 3.64 astronomical units from the sun (one astronomical unit is equal to the distance between the earth and the sun, about 150 million kilometers). Although there are more than one million asteroids in the asteroid belt, they are distributed within 150 million km, and the average distance between asteroids is 500000 km.
This distance is beyond the distance between the earth and the moon. The distance between the earth and the moon is only 380000 km. After reading this, I believe many friends have understood that the distance between asteroids is so far, in such a wide distribution, the probability of voyager-1 colliding with asteroids is very small, and scientists have basically ruled out this possibility. Unless Voyager one is out of luck.
The same principle applies to the Kuiper belt. The Kuiper belt has a wider range and encircles eight planets. Although there are a large number of asteroids, the distance between them is more than hundreds of thousands of kilometers. So the probability of Voyager 1 passing through this area is also very small.
Voyager-1 has lived up to the expectations of the public, and finally safely walked out of the top of the heliosphere, crossed the Kuiper belt and entered interstellar space. Some may ask, is Voyager 1 out of the solar system now? In fact, it is not. In the past, scientists’ understanding of the scope of the solar system was limited to the Kuiper belt. To go out of this area is to go out of the solar system and enter the extrasolar space.
But later, scientists observed the existence of the Oort cloud, so they extended the scope of the solar system to the Oort cloud, which is also a larger area around the solar system. If you include the Oort cloud, the diameter of the solar system is two light-years. If, according to the scope of the new solar system, voyager-1 is still in the solar system, it will take another 5000 years for voyager-1 to enter the Oort cloud, and then it will take tens of thousands of years for voyager-1 to cross the Oort cloud and walk out of the solar system.
Although scientists feel sorry for such a situation, it may not be a bad thing for human civilization. In fact, with the continuous progress of human science and technology and the continuous improvement of the understanding of the universe, scientists have regretted launching the Voyager spacecraft in 43 years. The reason is that the Voyager spacecraft carries a golden CD-ROM recording earth coordinates and human information.
If this CD falls into the hands of alien civilization, then we can know the existence of the earth and human beings according to the information recorded above. If this alien civilization is a kind and peace loving civilization, it is a good thing to say that coming to earth may bring us great help. However, if this alien civilization is an evil one that likes to invade and colonize, then the earth and human beings may face great disasters, and human civilization may be ended.
Hawking has repeatedly warned human beings not to try to contact with alien civilization. Before human beings are really strong, being attacked by alien civilization may not be lucky but a disaster. Fortunately, the possibility of this kind of worry is very small. Voyager 1 has not come out of the solar system, and the possibility of earth exposure is also very small. In the future, with the further development of human space technology, we can catch up with Voyager 1 and recycle its internal optical discs.
When human beings become interstellar civilization and have the ability of interstellar navigation, we can go out of the solar system and take the initiative to explore and find alien civilizations in various galaxies. Now we need to hide ourselves, quietly, until the day when we are really strong.
Guys, what do you think of this? Welcome to leave a message below to discuss and express your opinions.