This paper takes part in the series essay competition of “great science” of Recordunkown.
With the help of science and technology, human beings began to explore the planets in the solar system. And there are eight planets in the solar system, which one receives the most attention? I believe many people will say Mars.
That’s right. Mars is the planet that has been studied and explored most by human beings since they came out of the earth. Why do scientists focus on Mars? Some people may say that it’s because Mars is closer to us. In fact, Mars is closer to us, which is not the main reason. We need to know that Venus is closer to us, but why don’t we focus on Venus?
The reason why scientists pay the most attention to Mars is that the main purpose is to regard Mars as the second livable home for human beings in the future. When human beings walk out of the earth and see the vast universe, everyone knows that the future human beings will not shrink on the earth. Going out of the earth and immigrating to other planets is an inevitable way for human beings in the future.
Going to the interstellar and emigrating to the outer planet are the inevitable things for every civilization going to the interstellar. Due to the limitation of science and technology, the immigrating planets we can choose in the future can only be found in the solar system, and the habitable zone is undoubtedly the best area.
Livable with three planets, in addition to earth, Venus is a purgatory planet, surface temperature as high as 460 degrees Celsius. Such a bad ecological environment, human beings can not survive, even if we can transform Venus in the future to make it suitable for human habitation, then it is not the best choice for human beings. The reason is that Venus is closer to the sun, and the sun is also expanding, the temperature will be higher and higher, and the earth’s orbit will be hotter in the future.
Therefore, in terms of temperature, the new home we choose should be on the periphery of the earth, while Mars is the only one in the habitable zone. Although Mars is also very desolate, compared with the golden star, it has been regarded as a very excellent ecological environment.
Since the 1960s, scientists began to launch probes to Mars. In more than half a century, humans have launched dozens of probes to Mars. Through these probes, we have a better understanding of Mars. In 1964, when mariner 4 flew over Mars, humans took the first picture of the surface of Mars.
Before the probe arrived on Mars, we were still full of all kinds of fantasies about Mars, and some even fantasized about the existence of Martian civilization. But when the first picture of Mars was sent back to earth, we saw a world full of craters and dead.
Mars is very desolate. There is not only no imagined Martian civilization, but also no grass. It is a desolate world even more than the earth’s desert. Such a result naturally makes many people feel very depressed. Human beings are gregarious creatures, and naturally feel lonely when they see Mars.
So Mars is really desolate to nothing? With more and more probes landing on Mars, a picture of Mars back to earth, so that scientists began to become happy again. The reason is that a large number of research data show that Mars was not desolate, but a beautiful ecological planet no less than the earth, with a lot of liquid water on its surface.
Only later did Mars undergo drastic changes, which led to the deterioration of the ecology, the thinning of the atmosphere and the constant evaporation of water on the surface. On the surface of Mars, the probe found a natural environment similar to that of the earth, ancient rivers communicating vertically and horizontally, and moving land plates.
Although there is no liquid water on the surface of Mars now, there are many traces of ancient river beds. More importantly, the probe found ice and liquid water with high salinity on Mars. Scientists believe that there may still be a lot of water resources under the desolate surface of Mars.
Moreover, the probe has also found organic matter on Mars. These discoveries give us reason to believe that life might have been born on Mars billions of years ago, and that there might still be life under the polar ice sheet.
After walking out of the earth, human beings are full of strong curiosity about the existence of extraterrestrial life. If we land on Mars in the future and find Martian life, will it be good news? This may be good news from the perspective of searching for extraterrestrial life, but the answer given by scientists is frightening.
Human beings have been looking for extraterrestrial life. If life is found on Mars, isn’t that good news? I believe everyone thinks this is good news, because the discovery of life on Mars means that human beings are not alone in the universe.
But if we think about it carefully, we will find that the discovery of life on Mars is not a good news, but a complete bad news. Why do we think so? If only the earth has life in the solar system, it means that the birth of life is extremely rare. But if life is found on Mars, it means that life is not rare in the universe. As long as the planet meets certain livable conditions, life can be born.
How many habitable planets are there in the universe? At present, no one can give an accurate answer. The scientific and technological strength of human beings is still very backward. We don’t know how much the universe is, let alone how many livable planets there are in the whole universe.
We don’t know how big the universe is, but we can narrow it down to the Milky way. There are hundreds of billions of stars in the Milky way with a diameter of 100000 light-years, and there are basically a number of planets around the stars. Even if each star system has only one planet on average, there will be at least hundreds of billions of planets in the whole Milky way.
Even if the probability of habitable planets is only one in ten thousand, there will be a large number of habitable planets. There may not be less than hundreds of millions of habitable planets. Every livable planet has the conditions for the birth of life. With the existence of life, it is possible to evolve intelligent life similar to human beings. They may also establish civilization and develop technology silently.
The universe has a long history of 13.8 billion years, and the nodes of civilization must be different. There are so many galaxies in the universe, such as the Milky way, that we can’t test them all. Even within the observable range of human beings, there are at least trillions of large galaxies.
This means that there should be civilizations in the universe that appear about the same time as human beings, but also powerful civilizations that appear hundreds of millions or even billions of years earlier than us. It only took more than 300 years for human science and technology to develop to its present strength. Then the civilization in the universe has developed for tens of thousands of years more than human beings, and at least it has the ability of interstellar navigation.
Crossing distant galaxies is impossible for human civilization today. But for an interstellar civilization, long-distance Star Trek is not difficult for them at all.
In this way of thinking, the universe should be very busy, even if our strength is limited, we can not take the initiative to search for alien civilizations, and those powerful interstellar civilizations should not be difficult to discover the solar system and the earth.
But the reality is that we have not found anything, not to mention the traces of alien civilization, even the possible existence of the ball of Dyson and other more powerful traces of civilization, we have not found anything. Isn’t that strange?
The universe we see is a dead silence. Human beings are like a child standing on an isolated island shouting out, tearing his throat and not getting any response. Where are they all? If life is universal in the universe, then they should have contacted with human beings or left some traces of civilization.
Now we haven’t found anything, which makes scientists think of a possibility: the “big filter theory”, which was put forward by Robin Hansen in 1996. The “big filter theory” holds that from the beginning of life to the end of becoming an interstellar species, one after another hurdles need to be crossed, and one of these hurdles can hardly be crossed. This hurdle is the so-called “big filter”, which will eliminate almost all life.
The birth of life in the universe may be very common. As long as the livable conditions are met, life will be born and evolve. However, most of life can not evolve into intelligent life, even a small part of it eventually evolved into intelligent life and formed civilization. But later, it will be extinct for various reasons, completely disappeared in the universe.
If so, it means that human beings can not escape from the big filter. In the future, they may encounter a certain barrier and cannot cross it, which will eventually lead to the end and disappearance of human civilization. Therefore, if the existence of life is found on Mars, it means that there is a big filter in the universe. Because Mars life has not crossed that barrier, it has embarked on the road of extinction and finally become a passer-by in the universe.
It can be seen that if Mars finds life or traces of life in the future, it may be very bad news for human beings. After all, as intelligent life, human beings do not want to be passers-by in the universe, but can realize eternity.