Suitable temperature is the foundation of the birth of all intelligent creatures, of course, the universe is vast, and it cannot be ruled out that intelligent creatures can survive in harsh environments, however, more environmental adaptability, creatures that survive in this special environment are often unable to adapt to ordinary environmental factors, and they are more likely to die.

The existence of earth rifts means that there are drastic changes in the geographical environment of the planet, and the spillover effect of geothermal heat makes the temperature around the earth rifts, or the internal space of the underground, produce an activity space suitable for the birth of life.

Everyone nervously looked at the command screen, and a large number of unmanned reconnaissance ships took the earth rift as the key observation object, gathered around, launched reconnaissance aircraft groups, and explored robots,...... to explore the interior of the rift in the earth.

Soon, alien plants of different colors appeared at both ends of the cracks in the ground, stubbornly rooting on the steep mountain walls.

"Oh my God, there are really plants, so there is really a wisdom and civilization in it. Professor Smith's eyes widened, staring at the command screen, and he exclaimed excitedly.

"Not necessarily, not necessarily! Although the climate has eased and is suitable for life, the underground world environment has natural limitations, and it may not be possible to develop a smart civilization!" Professor Yang Yi shook his head excitedly with a trembling voice.

There is a huge difference between the development of the ground world and the underground world, they have also encountered an underground civilization in the Blue Pole Star before, due to the limited space of the underground world, the underground civilization has experienced tens of thousands of years of development, and still cannot develop an advanced civilization, not to mention, the planet with a harsher climate and environment in front of them, it is really unimaginable, what kind of underground civilization can be developed in the limited underground space, Professor Yang Yi's judgment was recognized by most people for the first time.

"No, I just think that the underground world is definitely not simple, you look at the length of this earth rift, it may be artificial, the purpose is to expand the space of the underground world. Professor Smith shook his head firmly and said no.

Hearing this, everyone frowned in unison, Smith's words were not unreasonable, the length of this earth crack at the moment was too long, and this special geological environment could not be easily created by the natural environment.

"Look, this set of isotope measurements shows that the planet's age is estimated to be about 3.87 billion years, which is a relatively stable planet, and the underground activity should be stable, so how did such a long earth rift come about? Why didn't it be bridged by squeezing?" Professor Smith pointed to a set of data on the command screen and looked at everyone and reminded.

Everyone looked at the data set that Professor Smith was referring to.

The age of the planet is measured by the decay period of the element, specifically by measuring the content of C12 in the substance, because the radioactive element has energy release, this energy release is equivalent to the change in the mass of the substance, E=MC^2, C12 This element continues to release energy, so the content of C12 is less and less.

When the content of this element is half of the original, the time taken is called half-life, and since the half-life of different elements is different, other elements with longer decay periods can also be measured.

The data that Professor Smith is referring to is the data detected by the Planetary Mechanical Corps in front of the more analytical Zircon (ZrSiO4) element, Zircon (ZrSiO4) It is a natural ore, uranium-lead dating method needs to use zircon, because uranium atoms and zirconium atoms are more similar, can be drilled into the lattice of zirconium instead of the original zirconium atoms, but the unstable uranium atoms will eventually decay into lead atoms, sealed in the zircon, the lattice of zirconium atoms only allow special atoms that meet the requirements of the charge to enter, so the lead element itself can not enter the zirconium atomic lattice, this unidirectionality for the determination of planetary geology to form accurate technical support.

The old planet that has undergone 3.8 billion years of precipitation, its orbit, geological changes,...... It has stabilized, just like the earth where the human mother planet lives, 4.5 billion years old, has an extremely stable star system, with 'stable' geological activities, otherwise, human civilization simply cannot spend so many years on a planet.

……

Everyone glanced at each other, and they were all shocked by Professor Smith's analysis, it is very likely that there is a highly technologically advanced civilization in the underground space of this planet, otherwise how could they develop a crack in the earth of such length.

"No, if this civilization can really develop this kind of technology, how can they still stay in the underground world, not to the ground, or to space? Professor Yang Yi frowned and retorted with his own opinion.

Professor Smith shook his head solemnly, and retorted: "No, they don't want to develop on the ground and in space, there must be other factors, maybe they have adapted to the underground environment, and it is not a matter of urgency to develop to the ground and space, besides, how to explain the incident of the xenomorph energy attack, it must be too coincidental!"

"I ....... Professor Yang Yi frowned, just trying to refute Professor Smith's speculation from other points.

At this time, Zhou Yu looked at the command screen with deep eyes, and stopped him in a loud voice: "Don't rush to make a conclusion yet, everyone pay attention to observe! The reconnaissance corps will uncover the mystery for us." ”

Hearing this, everyone was silent, their eyes staring closely at the command screen.

In the surveillance screen, there are images of countless reconnaissance robots exploring the cracks in the ground.

The unmanned reconnaissance aircraft flew into the bottom of the crack, 2,000 meters, 2,200 meters,...... , as if shuttling through a never-ending black hole, the unmanned reconnaissance aircraft has not been able to reach the end of the underground crack for a long time.

"The cracks ahead are shrinking!"

"Beware of complex terrain with raised rock formations!"

"It's not good, there is signal interference, the signal of the No. 176 drone was suddenly interrupted, and control was lost!"

"Immediately send additional signal balls for signal relay transmission. ”

……

In the flagship command room, the technicians on the console were busy and nervous, and all kinds of abnormal situations emerged one after another, constantly emerging, and with the assistance of Zhou Xiaozhi, the panicked remote control reconnaissance corps continued to go deep into the cracks in the earth.

Time flies, the cracks in the earth are deeper than everyone imagined, and the unmanned reconnaissance aircraft group has penetrated five or six thousand meters, except for the increasingly empty underground environment, and the spectacular and beautiful magical emergence of the underground world, there is no 'building' of intelligent civilization at all.

Difficult, all speculation is fake?

How deep is this crack in the earth! When will the unmanned reconnaissance aircraft group reach the bottom? Everyone's expressions gradually became impatient.

\bAt this time, the large holographic screen suddenly "boom, boom....... A large explosion of fire, the smart big screen watched the screen, and one by one fell into darkness.

"Not good, the No. 17 reconnaissance group hit an unknown substance and crashed en masse. ”

"Reconnaissance Group 11 also struck an unknown substance and lost contact. ”

"Reconnaissance Group 27 damaged 4 aircraft, found similar energy defense cover material. ”

……

The monitors on the console panicked and reported the damage to the reconnaissance fleet one after another.

The sudden launch of the change, everyone's spirits were shocked, and their eyes were staring at the command screen, waiting for the result to happen.

Soon, a scene that shocked everyone appeared, through the fire of the explosion of the reconnaissance aircraft group, a layer of light blue energy shield could be seen in the underground cracks, and after the unmanned reconnaissance aircraft group hit this layer of energy shield, they all crashed into it.

Everyone gasped in unison.

"Really, there is an underground intelligent civilization!"

"yes! I didn't expect this planet to ....... ”

"Are they the ones who attacked us? Why didn't they develop space power when they developed an energy shield?"

"This defensive shield is a magnetic shield, and it has a certain level of technology, but it doesn't seem to be a high level of technology!"

"Wrong, big mistake, you have to consider the length and range of this magnetic shield defense, this magnetic shield technology, I am afraid they have developed to the tip. ”

……

The flagship command room 'boom', suddenly chaos, after the experts and professors saw the defensive shield, the truth became clear, and everyone began to analyze the strength of this underground civilization on the strength of this defensive shield.

The magnetic shield is like an indestructible giant shield, blocking the unmanned reconnaissance group from continuing to explore under the cracks.

Now what?

Everyone looked at Zhou Yu one after another, expecting his order.

Zhou Yu lived up to expectations, looked at Zhou Xiaozhi and decisively ordered: "Send a broadcast to the other party and ask why they attacked us?"

Listening to Zhou Yu's order, Professor Smith's face changed greatly, and he hurriedly stopped him: "Ash, wait a minute!"

"Commander, the other party's combat strength has not yet been determined, and the broadcast in this tone is easy to cause disputes, so let's say hello in a friendly manner!" Professor Smith looked at Zhou Yu and said urgently.

"Yes, we don't know the details of this civilization at all, besides, our current combat power is limited, so it's better to be safe!" Yang Yijiao nodded again and again, agreeing with Professor Smith's words, and said to Zhou Yu.

The others looked at Zhou Yu and wanted to speak.

Zhou Yu stretched out his hand, ignoring everyone's reactions, and looked at Zhou Xiaozhi and decisively ordered: "Xiaozhi, immediately execute the order, and speak in a tougher tone." ”

"Obey, Commander!" Zhou Xiaozhi's face tensed, and he acted as ordered.

Immediately, the broadcast compiled by Zhou Xiaozhi was directly transmitted to the unknown civilization under the crack in the earth through the tunnel communication instrument.

Zhou Yu patiently waited for the other party's reply, his deep eyes fell on the holographic big screen, thinking about something seriously, but it was obvious that he was not thinking about Professor Smith's concerns, but about the comprehensive command of all the monitoring data on the big screen, from the effective intelligence, search for clues.

They also belong to the underground civilization, and the civilization in front of them is undoubtedly many times more powerful, they have mastered the technology of powerful magnetic defense shields, and at the same time, they also have ultra-long-range interstellar weapons, which can cause fatal damage to their warships.

Especially that kind of alien energy weapon, if the ordinary mechanical civilization encounters this strike force, the fleet will probably be wiped out long ago, so, judging from these two e-commerce, this intelligent civilization already has the strength to go to the outer sky, or, they have developed a suitable starship, but it is just hidden in a corner.

……

All kinds of thoughts continued to appear in Zhou Yu's mind one after another.

The holographic screen in front of Zhou Yu suddenly lit up and a large piece of unfamiliar text appeared, strange shapes.

Zhou Xiaozhi reported: "Commander, I have obtained the text information of the other party, however, the other party has not conveyed the auxiliary interpretation information, and it will take about 3 days to decipher, and the decipherment rate: about 47%. ”

Hearing this, Zhou Yu's expression tightened, and he asked one after another: "What communication method did the other party use, and why were they able to decipher our information so quickly? Is their computer more powerful than yours?"

"Commander, this message was not sent by radio, nor by quantum entanglement of ultra-distant communication technology, but in a way similar to space broadcasting, and the transmission speed took only 0.3 seconds. Zhou Xiaozhi took the lead in answering Zhou Yu's first question.

After a pause, Zhou Xiaozhi continued: "Commander, the information I transmitted used scientific keys and marked the translation structure, so the other party can easily translate our message into their own language and understand it, it takes no more than 20 seconds, and their computing power is about three times higher than mine, but Xiaozhi is better than their computer in other aspects." ”

The scientific bond is the use of the universe in physics, mathematics, chemistry,...... Its biggest use is that when there is a communication barrier between the two civilizations, you can use scientific keys to decode and translate.

As long as the intelligent civilization has a little research in the field of scientific research, they can use this scientific key to easily interpret the other party's information and the accompanying meaning of the information.

"It makes no sense to ask for decoding tools, or the scientific key structures they provide, otherwise we won't have any communication with them. Zhou Yu had a dark face and looked at Zhou Xiaozhi and ordered stiffly.

"Okay, Commander!" Zhou Xiaozhi gladly complied.

Everyone Bi Chi glanced at each other, and they all felt helpless about Zhou Yu's tough attitude, now this civilization has not yet exposed the true details, after data comparison, the scientific and technological level of this unknown civilization is obviously decades higher than that of human civilization.

However, Zhou Yu didn't know if he had taken the wrong medicine, and he was not polite to this enemy who was stronger than himself.

"Commander, I received a message from the other party, and the other party sent the scientific keys they had compiled, and the information had been successfully compiled. Zhou Xiaozhi looked at Zhou Yu and reported.

"What is the information? Quickly call up the news!" Zhou Yu was shocked and instructed Zhou Xiaozhi.

"Okay, Commander!" Zhou Xiaozhi responded.

Immediately, the conductor's large screen changed to present a mixed passage of Chinese and English.