"Is the radio telescope array on the moon complete?"

"Commander Lu, the arrangement has been completed."

"What about the space-synchronous orbit?"

"This is also complete, and the final activation test is underway."

Yangcheng Laboratory, which is the command center of this alien civilization warship incident.

According to the regulations stipulated in the previous signing of the Mars exploration program agreement, when encountering aliens, the Mars exploration program team will be responsible for the relevant exploration exchanges.

Now not only have all the members of the Mars exploration team canceled their vacations and come to Yangcheng, but Russia and the United States have also sent new experts here, and the aerospace department of Tomorrow Group has been entrusted to Huaguo.

China's 10 million-ton warship is about to be completed, and more of the country's strength is placed here.

Not only is China's large warship about to be completed, but the progress of Russia and Lao Mi is not much slower, and in the earth's space orbit, three large space docks are receiving a large number of equipment and materials delivered from the earth by small starships every day.

A warship with a mass of 10 million tons can only be built in space due to the existence of the Shiloh limit, otherwise it will not even be too close to the earth, let alone the ground rise, because the gravitational tide of the earth will tear the battleship apart.

"Where's Tomorrow?"

After confirming that there were no problems with several large detection arrays, Lu Yi walked to the aerospace department of Tomorrow Group and asked about the situation of Tomorrow.

The technician called up the tracking data of Tomorrow and replied: "Tomorrow has accelerated to 1,800 kilometers per second, and it will reach Pluto in about 25 days." ”

After a month of renovation and a life-sustaining system, Tomorrow went to Pluto four days ago with some exploration equipment and two astronauts to search for the legacy of the Muba civilization.

The only pity is that the current position of Pluto is not consistent with the direction of the alien civilization warship, but there is still an offset of more than 60 degrees, otherwise it will be possible to continuously track the traces of the alien warship by transporting large deep space exploration equipment directly with the Tomorrow.

"After Tomorrow arrives at Pluto, the device will be physically separated from the device and a satellite communication network, and it will be disconnected from other equipment and the network, and then it will be connected to Tomorrow."

This time, the Tomorrow Number is mainly to search for the inheritance number of the Muba civilization and determine the embryo situation inside, and it will not link to open the data on the inheritance number, but for the sake of insurance, Lu Yi still tried his best to ask for a special communication route to contact the Tomorrow number.

"Commander Lu, this is the latest image captured by the radio telescope array above the moon."

At this time, Comrade Lao Su took a report and said: "After the analysis of the data, this alien warship has accelerated again, and the current speed has reached 980 kilometers per second, and there are still 65 astronomical units from the earth, and we have captured their engine screen for the first time. ”

"Engine screens?" Lu Yi hurriedly took the report.

"Here, these pixels."

Lao Su pointed to the image on the report and said: "I was blocked by the main body of the opponent's battleship because of the angle before, but this time because of the change in orientation, I just scanned the tail of the opponent." ”

"Working fluid impulse engine, through the spectral analysis of exhaust gases, is hydrogen, helium and oxygen?" Lu Yi glanced at the image a few times, flipped through the data analysis behind it, and thought quickly in his mind.

"This alien battleship is either camouflaged or something is wrong."

After thinking for a while, Lu Yi said affirmatively: "I guess that the propellant of their warship should be exhausted, and they are collecting the thin hydrogen-helium element and water in space as a propellant while sailing.

No wonder the acceleration behavior is the same as diarrhea, accelerating every once in a while, speeding up every once in a while. ”

Comrade Lao Su thought for a while and said: "If something goes wrong, it can probably determine the purpose of the other party's entry into the solar system, and can also determine the approximate scientific and technological level of the other party. ”

If there is a problem with a battleship, it is a living coffin in space, and it cannot be repaired if you want to, because there is not enough material in the space between galaxies.

In this case, the battleship's only choice is to either use the last energy and matter to locate the direction, and use inertia to float back to the home star after speeding up, or to find a nearby galaxy to replenish the matter and repair the battleship.

"There is no elemental spectrum of carbon detected by scanning in the exhaust gas, which means that the other party's nuclear fusion technology is either DT fusion or DD fusion."

Lu Yi shook his head and said: "But you can roughly determine the other party's scientific and technological level first, and don't comment on the other party's purpose first."

The devil knows if there is a real problem with their battleship and they want to enter the galaxy to repair it, or if they want to come in and fight a wave of autumn wind. ”

The advantage of a controlled fusion engine is that it does not require much propellant, as long as it is a gas with a better coefficient of expansion.

However, under normal circumstances, humans use hydrogen and nitrogen, which is used in the atmosphere, and when it enters space, it is replaced by hydrogen with a better expansion coefficient.

This is also the reason why Lu Yi determined the other party's situation from the elemental spectrum of the exhaust gas of the opponent's engine, because the spectrum of oxygen elements will not appear in the exhaust gas of the nuclear fusion engine at all, and at the same time, the storage conditions of liquid helium are more harsh, and it is generally not used as a conventional propellant.

Combined with the other party's thin-like acceleration behavior, this oxygen element is most likely to be obtained from the thin water in space, and the helium emission may be the exhaust gas of nuclear fusion, or it may be collected from space.

At the same time, the degree of nuclear fusion technology of the other side, which can also be known from the information on the exhaust gas.

Deuterium-tritium fusion, that is, the product of DT fusion is helium, deuterium-deuterium fusion, that is, the product of DD fusion is hydrogen, and the product of helium fusion is carbon, and there is no carbon in the exhaust gas of the other party, then it can only be DT fusion or DD fusion.

"Intensify tracking."

Handing the report in his hand to Lao Su, Lu Yi said solemnly: "The other party is approaching, and we have a greater certainty of scanning and capturing the other party's traces, and at the same time, the other party is more likely to show some valuable information." ”

......

Far away outside the Kuiper Belt, the sun is as dim as fireflies dozens of meters away.

In this dark starry sky, a warship with a dilapidated surface and traces of melting and solidification is sailing at high speed, and every once in a while, the main engine of the battleship will shoot out a plasma beam, and the strong recoil force generated will increase the speed of the battleship by a fraction.

"Blu-ray, how far are you from entering the core of this galaxy?"

Octopus-like creatures breathe bubbles in the blue-blue transparent liquid, sending interrogating electromagnetic waves to the battleship's intelligent systems.

"Captain, there's still 9.6 billion kilometers."

"I remember that the effective detection range of our remaining deep space exploration module is 8 billion kilometers, can the speed of the warship be accelerated? I can't wait. ”

The captain waved his tentacles, and it was clear from his body language that he was already in a little anxious, just like the feeling of anticipation in his heart when waiting for the girl he loved.

"Captain, our material collector has only partially repaired, and it can only be accelerated intermittently."

The blue light replied that the original battleship's retained propellant could only accelerate to 560 kilometers per second, and it took more than two years to enter the solar system.

However, as we got closer to the solar system, the density of matter in the starry sky began to increase, and the speed of the battleship could be increased to 980 kilometers by using the repaired material collector to collect hydrogen, helium, and water as propellants.

The closer you get to the solar system, the faster this one will accelerate, because the denser the matter will hinder the ship's speed.

However, with the gradual increase of the sun's gravitational pull, the gravitational acceleration effect and the excess energy output of the nuclear fusion reactor, the energy obtained by the battleship will be greater than the energy consumed by the blockage of matter.

"Then you can turn on the deep space exploration module and let me know." The captain was silent for a moment, then continued to sink to the bottom and began to rest.

It is different from the fact that humans are now equipped with large detection arrays on the ground, on the moon, and in space to continuously track this warship.

The size and space of the warship determine that it is destined to be impossible to use this array detection method, if it cannot be detected through a large array set, then the accuracy of the information obtained at such a long distance is very low with one module or three or five modules.

Therefore, if the warships of the Blue Civilization want to know the situation of the solar system, they must either enter the inner galaxy circle and collect information at close range, or use ultra-high-power active modules to transmit detection waves, and then collect and analyze the reflected waves.

The deep space detection module of the warship of the Blue Civilization is such an active detection technology, and it still belongs to the category of electromagnetic waves, just like the radar of human beings, but the power, detection progress, and technical details used in this radar are different.

Fifteen days later, the Blue Light Battleship, which had accelerated several times to increase its speed to 1,086 kilometers per second, finally reached the 8 billion kilometers range of deep space exploration.

"Captain, if we start the detection now, the civilization in this galaxy will be able to directly discover us." Zhang Jianlei and Garcia, a crew member, said with some hesitation.

"Just let them find out!"

The captain waved his tentacle and said calmly: "Remember, we are peace messengers, we are here to communicate, not to war, you sneak into the scope of other people's civilization, so how can you communicate peacefully?"

Garris, check if there is a problem with the deep space exploration system. ”

"Captain, the detection system is fine." A few minutes later, another crew member, Garris, replied after confirming it.

"Blue light, increase the reactor power, turn on the detection!" The captain then ordered.

When the command was issued, the blue light of the intelligent system began to increase the power of the warship's nuclear fusion reactor, and the surging energy continued to emerge from the supercapacitor group of the detection system......

After nearly 10 minutes of energy storage, the energy stored by the supercapacitor reached its peak, and then the valve opened, and more than 100 million kilowatt-hours of energy emerged from the launch module of deep space exploration.

Airplanes!

A part of the remaining air in the battleship made a sound under strong static electricity, and the deep space exploration module emitted two high-intensity detection waves to scan the interior of the solar system.

The frequencies of these two detection waves are very peculiar, and they resonate with each other while moving forward at the speed of light, and this entangled resonance is generating a wide-area signal of the third frequency.

The high-intensity detection wave lasted for ten minutes before it subsided, and according to the distance, it will reach the Earth in 7 hours and 24 minutes, and then in nearly 15 hours, a detailed and clear detection of the civilization in this galaxy will be obtained......

"Zhang Gong, I found an ultra-high-intensity radar scan from Kuiper out-of-band!"

In less than seven hours, two astronauts aboard Tomorrow, which was on its way to Pluto, were the first to spot the sounding wave from outside the Kuiper Belt.

"Kuiper out of the belt?"

The astronaut who was called Zhang Gong heard that Kuiper was outside the belt, and the sensitive nerve in his heart was stirred when he knew that the alien warship was approaching the earth.

"Do we need to report back to the other side of the planet?" Another astronaut couldn't help but ask when he saw Zhang Gong's expression.

He is a biology major, and he came to verify whether the embryos of the Muba people are still viable.

“......”

Zhang Gong, who was originally worried, heard this, and the corners of his mouth twitched: "Go back and review physics well, your report has not yet reached the earth, and the earth already knows about it." ”

As soon as he finished speaking, Zhang Gong seemed to think of something and asked, "Wait, we brought 30 electromagnetic pulse nuclear bombs, right?"

We calculate the time according to the speed of light, and launch 10 EMP nuclear bombs between the Earth and the signal source in turn to see if we can block their echo feedback! ”

In order to prevent the information virus mutation or trap of the Muba Civilization Inheritance, the Tomorrow is not equipped with weapons, but it carries 30 large-yield electromagnetic pulse nuclear bombs.

According to the distance between Tomorrow and the Earth now, if the other party's detection and scanning technology is similar to that of human radar, then Tomorrow will drop 10 pulse nuclear bombs in turn, which is very likely to interfere with this detection.

Drip, drip, drip!

At 7 hours and 24 minutes, in the Yangcheng Laboratory, everyone who was busy tracking the alien warship was awakened by the sudden sound of the alarm, and the huge screen in the center of the hall changed for the first time, showing the information of the alarm.

"Commander Lu, the high-intensity radar scan from outside the Kuiper band is amazing!"

"The starting point of the signal source is 8 billion kilometers away from us, and it is the alien battleship! They're waking us up to active scanning and detection, oh my God, 8 billion kilometers of active detection! ”

Everyone was stunned by this alarm message, and the active scanning and detection of 8 billion kilometers has surpassed the current technological imagination of human beings.

"Commander Lu, this is the frequency data of the other party's active detection wave."

In less than two minutes, the engineer who detected the radar took an emergency analysis data to Lu Yi, and said with a somewhat solemn expression: "It's just very strange, we found that the frequency of the other party's detection wave has 3 frequency bands." ”

"Commander Lu, the Tomorrow sent a message saying that they are going to calculate the echo time of the other party and try to throw 10 electromagnetic pulse nuclear bombs to block the detection echo."

At this moment, the technician in charge of contacting the Tomorrow spacecraft came over and told the situation reported by the Tomorrow.

"An electromagnetic pulse nuclear bomb?"

The person next to him was stunned, and said with a strange and somewhat happy expression: "Lao Zhang is awesome this time!" I just don't know if the echo blocking was successful. ”

"It's useless, blocking won't have an effect, the technology used by the other side is not the same as our radar technology."

Lu Yi looked at the data analyzed by the detection radar engineer, looked at it for a while, shook his head and said: "In addition to blocking with high-density and high-thickness objects, this kind of scanning detection cannot do other blocking interference or shielding and absorption. ”

"Keep tracking them, it's already a bit bad." Lu Yi took a deep breath and motioned for everyone to continue tracking.

The other party is actively scanning and probing from such a distance, and such an active exposure means that the probability of the other party being malicious has decreased, but this does not mean that the other party is not malicious, because this may be tactical deception.

If you really want to come to the solar system to replenish materials or go on vacation, lest it cause misunderstanding, so say hello in advance, then send an electromagnetic wave over, and attach a language dictionary, why bother to have such a vast deep space exploration scan.

What's even more troublesome is that such a large intensity of scanning and probing also means that this matter cannot be hidden from the outside world, which is the worst, which is likely to cause the whole thing to get out of control.