Plants have begun to appear on the planets. They are not very tall, with small leaves and simple structure.

We soldiers, usually have no entertainment after training, just bets. If the incident of not paying off the debt will spread, then the brothers will think that my character is not good, and no one will support me. Then the general will easily destroy me? No, it is important, I will go. The imperial army has set off.

On this planet numbered Border One, troops from the Free Federation and the Imperial Federation appeared. Logically, there were only one star around, and there were at least thousands of stars nearby, and the probability of a collision was very small. The problem is that everyone was interested in this place. There was only one planet in the habitable zone of this star.

"habitable zone" actually refers to a certain distance around a star, within which water can exist in liquid form. Since liquid water is considered an indispensable element for the survival of life by scientists, if a planet happens to fall within this range, it is considered to have a greater chance of having life or at least having an environment in which life can survive.

The "livable zone" is also called the "livable zone". It is discussed in multiple life objects. Generally, it is studied as the "livable zone of animals". For any animal, plant, and even microorganism, there will be a zone that is most suitable for its survival. If all organisms on the earth and the different conditions required by them at different stages of evolution are summarized, and these conditions are extended to the required planetary conditions, the conditions of the sun, and even the conditions of the star system, the concept of "livable zone in the universe" is formed.

Most of the space in the universe is a dangerous place for life. Only a few places can become an oasis of life and provide the right atmosphere, suitable temperature, liquid water for the emergence and development of life. It is difficult to reside in life in the empty space, hot stars, and gaseous planet surfaces. It seems difficult to clearly give the environmental conditions required by life. After the earth provides the most basic environment for life, it provides a perfect habitat for life in any aspect, and the earth is the only planet with life discovered so far. The discussion of the "cosmic livability zone" needs to be carried out from several aspects such as space, time, and biodiversity.

For astronomers, "potentially habitable" planets are the kind of planets that can sustain life but may not necessarily allow humans to survive. Habitability depends on many factors, but liquid water and atmosphere are the two most important factors. The gravity of a planet will cause the radial velocity of its main star to change regularly, while multiple planets will cause complex swinging activities to move its main star.

As an ideal place for living various lives, one of the most important characteristics of the earth is its location, that is, its distance from the sun. The most suitable distance from the sun is the basis for defining the "hobby zone", where there may be planets similar to the earth. Planets in the habitable zone will receive the heat radiated by stars, which will not freeze the water, nor will it boil more water, just maintain a liquid ocean.

The range of the habitable zone should be defined by the low temperatures at the outer edges and the high temperatures at the inner edges. The two neighbors of the solar system, Venus and Mars, give examples of the external boundaries of the habitable zone. If the distance is close to the sun, there will be no liquid oceans on the surface of the planet, like Venus; it will be frozen too far.

If the earth is moved outward for some distance or weaken the solar radiation, the surface temperature of the earth will be reduced until it is covered by ice and snow. Gradually, the carbon dioxide is frozen, forming a cloud of dry ice particles, and eventually they are frozen at the poles to form an ice cap. The width of the habitable zone depends on the similarities and differences between the planet and the earth, as well as the size and age of the stars.

On the surface of a rocky planet with a certain carbon content, if there is a stable liquid ocean, it has the conditions to generate and reside in life.

For terrestrial planets, the habitable zone of animals is a range: the planet can maintain a liquid ocean on its surface and can maintain a global average temperature below 50°C. This temperature is basically the upper limit of the living conditions of animals.

If you consider the living environment of the present intelligent life, you will get a narrower "living zone": that is, a planet that can grow enough crops for intelligent life to eat. On the contrary, a wider and easier to define habitable zone is the "living zone" for microorganisms to survive: it almost includes the entire star system and has been formed in the stellar system until now. For other types of "living zones", it should be wider than higher organisms but narrower than microorganisms.

Then, the two troops met. As soon as they met, the troops on both sides were swearing, don't make a noise. Don't let the other party know that we are here, otherwise it would be embarrassing to meet. Report to the superiors quickly and say that we have encountered the main force of the enemy, with three to five million people, so the leaders must send 3 to 50 million people to eliminate the other party.

In fact, there is an army on both sides, with a full 10,000 people. However, if you don’t talk about three to five million people, the leader will not care about us, haha. The leader is not stupid. Send a reconnaissance force quickly, and after all, it will only be ten thousand people. You can solve it yourself and strictly order it, so you can’t suffer any losses.

The people on both sides settled down. Logically speaking, it is difficult to meet such a large planet with 20,000 people. As a result, the places where both sides deployed were similar. Perhaps the people who chose the locations were all graduated from the same class in the same military academy. Fortunately, the place where they landed is more suitable for hiding. In a cave, a team of soldiers from the Imperial Federation were resting in the cave. We were staying well at home, why did we come here? Who are we? Where are we? The soldiers in this company have several civilizations, and they all look strange.

"Company Commander, what are we doing here?" Someone asked his company commander.

The company commander was squatting in the corner, "I don't know either!".

"It seems that I'm not here to fight, otherwise we can't help but fire guns, right?"

The gun is the life of a soldier. The company commander has asked his superiors for guns several times, but the leader does not give it to him. Hey, the company commander's heart is cold. After all, it is still a matter of money. The military expenditure is insufficient, so only some soldiers have weapons. Most of them follow them to make soy sauce.

The company commander was also confused, "I don't know what my superiors think, why are we here for. You can see this place, even if it's for defense against wild animals, you should give us some weapons, right? Let's make our own spear!"

The error-free chapters of "Testimation of Civilization" will continue to be updated on the novel website. There are no advertisements on the site. Please collect and!

If you like the Witness of Civilization, please collect it: Witness of Civilization is updated the fastest.
Chapter completed!