The earth is a beautiful planet of life. Before mankind got out of the earth, we didn’t know the vastness of the universe, and we didn’t know what position the earth was in the universe.
With the continuous advancement of human technology, we have stepped out of the earth and finally saw the vast universe. At this time, we understand how small the earth is. From the perspective of the universe, the earth seems to be very ordinary, nothing special, but with the continuous improvement of observation technology, we have discovered a lot of planets. Through comparison, we can clearly see that the earth is unique and a very A beautiful planet, perhaps this is the characteristic of the planet of life.
When humans have seen the vastness of the universe, they naturally have a keen interest in the existence of extraterrestrial life. Whether it is from the perspective of the vastness of the universe or the age of the universe at 13.8 billion years, there is no doubt about the existence of extraterrestrial life, but scientists have spent more than half a century of hard work, until now they still find any traces of extraterrestrial life.
Despite this, scientists still firmly believe that extraterrestrial life exists, but the solar system only has the earth as a beautiful ecological planet, and there may only be the earth as a life planet. To find alien life, we still need to look at the stars outside the solar system.
Through the characteristics of the earth as a living planet, we can also provide a certain direction for us to find extraterrestrial life. Since the earth can become a living planet 3.8 billion years ago, it shows that the ecological conditions of the earth meet the various factors required for the birth of life. So relying on the ecological conditions of the earth to find extraterrestrial life is a very good direction.
So why can life be born on the earth? It is mainly due to its suitable temperature, suitable atmosphere, air composition and liquid water and so on. The combination of these conditions finally gave birth to life on the earth, and after a long period of evolutionary evolution, human beings were born.
And there is no second planet in the solar system that is very similar to the earth’s ecology, so we can only put our field of vision outside the solar system. In order to find terrestrial planets that are very similar to the Earth, in the 1990s, scientists launched an optical telescope into the Earth’s orbit. I believe many friends know who it is, that is, the famous Hubble Telescope.
The lift-off of the Hubble Telescope has extended human vision to the depths of the universe, and it has recently been able to see 13 billion light-years deep. Through it, we have a deeper understanding of the universe, allowing us to see what the universe was like 13 billion years ago. Through it, we have a deep understanding of the evolution of the celestial bodies and galaxies in the universe, and the Hubble Telescope also occupies a huge contribution to the proposal of the Big Bang theory.
It may seem to many people that the universe is dark and empty, but in 2012, NASA released a Hubble extreme deep field photo. This photo shows the Hubble telescope facing a very small space (only the full moon). 1/10 the size of the area), a long time exposure was taken, and a picture was taken.
A small piece of starry sky that is dark and empty in our eyes is a different sight in the field of view of the Hubble Telescope. From the picture, we can see that the whole picture is full of bright spots of stars, and these bright spots are all galaxies similar to the Milky Way. It can be seen that the celestial bodies in the universe have a huge amount of star coefficients.
There are about 10,000 galaxies in this small picture, and the oldest galaxy is 13.2 billion years old. Among so many galaxies, there is no shortage of terrestrial planets that are very similar to the Earth. It’s just that human observation technology is not advanced enough. Although the observations are very far away, we can only observe galaxies closer to the earth if we want to get more information about a certain galaxy.
Scientists have used some scientific methods such as transit method, direction-of-sight velocity method, microlens method, etc., so far more than 4,500 exoplanets have been discovered. Among these planets, scientists are still focusing on those that are very similar to the Earth. Only terrestrial planets that are very similar to the Earth are more likely to have life.
Some time ago, in the journal “Astrobiology”, scientists published a paper. The paper showed that the scientists re-listed some of the standards that a super-habitable planet should meet, and according to these standards, they have discovered more than 4,500. Exoplanets were screened and the best 24 candidate planets were found.
These 24 planets are just from the outside, they are very similar to the earth, and they also have a beautiful color. When we judge the ecology of a planet, we can get a rough data by comparing some of its appearance with the earth. The main star of the galaxy where these planets are located is a K-class star, and our sun is a G-class star.
The lifespan of a G-class star is only about 10 billion years, and it takes a very long time for life to evolve from the primitive stage to the intelligent stage. It took 3.8 billion years for life on Earth to evolve to the stage of human birth. This is actually a It’s a relatively short time. If the time is longer, the earth may not be able to wait for the day when mankind is born.
Therefore, G-class stars like the sun are not ideal host stars for the birth and evolution of life. On the contrary, K-class stars are more superior. Their mass is smaller than that of the sun, and their lifespan can reach 20 to 30 billion years. They can support the evolutionary evolution of life for a longer period of time. It is more hopeful that intelligent life will be born and developed step by step. Become an interstellar civilization.
Among the 24 planets, one planet is about 5 to 8 billion years old, which is much older than the age of the earth. In addition, it has a beautiful ecosystem. Scientists speculate that life may have been born on this planet, and it may even have evolved into an intelligent civilization.
According to observation and analysis, the surface temperature of this planet is about 3 degrees Celsius higher than that of the earth. This temperature is equivalent to the tropical rain forest area of the earth, and it is a temperature very suitable for the survival and evolution of life. From this we can also think that there is a high probability that liquid water exists on this planet, and there is also a very thick layer and magnetic field.
The atmosphere of this planet has an oxygen level of 25%-30%, and most of the rest is inert gas. This is very similar to the atmosphere of the earth. It is a planet that is more suitable for human survival than the earth. In addition to this planet, which is more suitable for human survival, the other 23 planets are also not bad. There is a high probability that life exists, and it may also be an ecological planet that is more suitable for human survival.
Although these planets make us look forward to, and hope that one day we can emigrate, we also have to consider two issues. One problem is that the 24 planets are basically thousands of light years away from the earth. Although this distance is nothing in the universe, it is an insurmountable gap for mankind.
If humans want to reach such a distant galaxy, our spacecraft must achieve superluminal flight. There are only two ways to achieve superluminal speed. One is a wormhole, and the other is a curvature engine that scientists have been studying. The most promising thing in the future is the curvature engine, which allows the spacecraft to break through space and achieve super-light speed shuttles.
Another issue to be considered is that these 24 planets may already have intelligent civilizations. If this is the case, it is basically impossible for humans to migrate, unless they are forcibly occupied through interstellar war, but this will be very costly for humans. Moreover, the ages of these planets are much older than that of the earth. If life was born much earlier than the earth, then the strength of civilization may also be much stronger than that of human beings.
It can be seen that it is the same thing to find terrestrial planets similar to the Earth, but it may be much more difficult to achieve migration. There are a large number of habitable planets suitable for human survival in the universe, but with such a beautiful ecological environment, there is a high probability that life and even civilization will be born.
Therefore, even if humanity becomes an interstellar civilization in the future, it will not be easy to truly find an ownerless planet suitable for human existence.