"The first habitable galaxy we found in the Milky Way was the Solar System, which has several planets suitable for human habitation, of which the Earth has the best environment."

Zhang Binhui's heart beat violently, and he finally talked about the history of our earth.

Teacher Cai continued: "As we all know, the development of the earth occurred before the history of galactic warfare, and at that time, we humans had not yet encountered aliens.

The two immortal level cultivators, Zhu Rong and Gonggong jointly led the team to launch an interstellar expedition, and their luck was good, and after spending hundreds of years, they finally found the galaxy and discovered the earth.

Everyone knows that Gonggong represents the power of the family, and he rebelled. The environment of the earth is very good, and Gonggong wants to swallow the earth alone, so he sneaks up on the entire fleet.

Zhu Rong immediately discovered the conspiracy of the co-workers and rose up to fight against it. The combat power of the two immortal-level cultivators was incomparable, the environment of the earth was seriously damaged, and the spiritual veins were completely destroyed by them.

The strength of the two cultivators was equal, and they both died together, and Zhu Rong sent back the coordinates of the earth.

Everyone knows what happened after that, the galaxy broke out in the alien frenzy, and humanity was busy fighting for survival, so our galaxy exploration came to a halt, and all the power of humanity was used on the battlefields of several major planets, and the earth was abandoned by us.

The Earth has no potential for development, it has become a penal colony for our criminals, who thrive on the planet, and now it has turned into a technological planet, and the Alliance's obligation to the Earth is only to keep it safe. ”

What Mr. Cai said is exactly the same as what Chi You said, the earthlings are really the descendants of the remnants of the galaxy, and we are not evolved from apes.

Zhang Binhui sighed lightly, not knowing what it was like in his heart.

Our ancestors are more advanced, but our environment is congenitally insufficient, and the mystery appears in front of him, but Zhang Binhui is a little confused.

He was unwilling.

Galactic criminals, that is also his personal problem, hundreds of thousands of years ago, should not be borne by their descendants.

The alliance only provides security guarantees, but does not provide development support, which is unfair to the people of the earth, and time has washed away all evils!

Thinking of this, Zhang Binhui raised his hand hesitantly, and Teacher Cai Lin looked at it with a smile:

"Do you have anything to ask?"

Zhang Binhui asked: "Teacher, where have we developed in the galaxy?" Have you found an environment similar to the solar system? ”

Teacher Cai smiled and motioned for Zhang Binhui to sit down:

That's a good question. In the Milky Way, we have made discoveries. In the past hundreds of thousands of years, we have discovered two habitable galaxies in the Milky Way, namely the solar system and the ascending system.

The Mingsheng system was discovered after the solar system, three hundred and fifty light-years away, and the environment there is also good.

Now we are cultivating the ecological environment of Planet 4 of the Mingsheng Galaxy, which has not yet been named, but the environment is completely habitable, and it has the hope of becoming the first cultivation planet of our human beings in the galaxy. ”

The audience immediately burst into warm applause, which was another great victory for our humanity.

But Teacher Cai Lin immediately sighed:

"It's a pity that our human exploration has stopped. Because of the appearance of the aliens, we have changed the direction of development, and more energy has been spent on fighting aliens, and our interstellar exploration work has basically come to a standstill.

All the resources were sent to the Scorpio constellation, where planets 1, 2, and 3 were like a big mill, and how many resources were thrown down disappeared in a blink of an eye.

The Milky Way is a large galaxy with great prospects for human development so far, and it is expected to become the third galaxy developed by our human beings after Andromeda and Centauri.

As we all know, the universe is endless, and the distance between planets is extremely far, so it is not easy to explore a habitable planet.

We have done data analysis in the Milky Way, and the number of habitable planets there may be tens of billions. ”

"Wow", as soon as this data was thrown out, all the students in the audience gasped. Tens of billions, this number is too terrifying, it is no different from the Andromeda constellation, and Andromeda is the constellation of the origin of our human race!

Teacher Cai Lin obviously expected everyone's reaction, she smiled, and then explained the reason for this data.

"Our research focuses on red dwarfs, which are considered the true face of most stars in the universe. According to our analysis, about 40% of red dwarfs have habitable planets around them.

This means that there is a suitable temperature there, and if a comet has hit them, the water on it can remain liquid.

The only problem now is that we haven't had time to find out how many of these potential water worlds are rocky planets, and if they are gaseous planets, rocky planets are habitable planets that meet our needs. ”

"What do you mean......" Zhang Binhui continued to ask: "The location and environment of the star itself are the most important, is there water that we humans can solve by ourselves?" ”

Cai Lin nodded:

"That's right. A red dwarf star, which belongs to the m-type main-sequence star. Its surface environment is different from that of a g-type main-sequence star like the Sun, which appears cooler and smaller, and has a longer lifespan than our Sun because the fusion of hydrogen nuclei inside is less violent.

We found that about 40% of the 160 billion red dwarfs in the Milky Way are surrounded by planets that are similar in size to Earth, and that these planets are in orbits at a suitable distance from the red dwarfs.

This means that these huge planets already have the temperature environment for the presence of liquid water, which is necessary for the emergence of life.

According to our calculations, there are about tens of billions of planets in the Milky Way in the habitable zone, so we say that the Milky Way is a veritable 'habitable galaxy'. ”

Teacher Cai Lin clicked on some light spots in the star chart:

"Not every planet is going to have water, and water is a necessity for our human survival, so we need to modify the environment of these planets.

In the universe, comets are the largest source of water, and most of the water sources on habitable planets are left behind by comet impacts.

For example, the earth in the solar system, such as the crape myrtle where we live now, they all left a source of water on the planet a long time ago due to the accidental impact of a comet.

But we humans don't have time to wait for a comet to strike, and it is also extremely difficult to find such a perfect planet, so we intervene manually.

For example, the Mingsheng Galaxy I mentioned earlier, we have three high-level engineering teams that are carrying out transformations there, and there is no water on Planet 4 of the Mingsheng System, but the conditions there are quite good, so the Alliance decided to transform it. ”