Tang Yue carried the solar panels onto the board car of the Martian stray dog, the isotope temperature difference generator and the battery were in the car, the old cat was about to travel far away, the latter did not need food supplies, but the power reserves must be sufficient, Tang Yue gave all the batteries that could be loaded into the car and taken away to the old cat.

It is foreseeable that after the comet Tomcat-Tang-Mai hits Mars, it will cause extremely serious derivative disasters, and the old cat may be able to avoid the impact and earthquake, but the large amount of material thrown into the sky during the impact will plunge Mars into endless darkness, and the dust that covers the sky will completely cut off the source of solar energy, which is the main problem that the old cat will face.

So Tang Yue loaded all the batteries into the car, and he was worried that the old cat would not get enough power to replenish it.

The old cat comforted him and said that the atmosphere density of Mars is low, the wind is weak, and the smoke and dust will not stay in the air for too long, so it is a big deal to turn off the machine and enter a dormant state, and first get through the darkest period, just like the Chelome probe, humans cannot go more than three minutes without breathing, but the old cat can sleep for a long time on standby to minimize power consumption.

As the saying goes, hibernation.

Tang Yue walked around the Martian stray dogs, patting the cab and wheels of the Mars rover, the old cat and Tang Yue lacked the tools to repair the stray dogs, so the broken car was still covered in bruises.

The previous stray dog was a husky.

Now it can only be said that it is a pit bull.

"You've worked hard, too." Tang Yue put his palm on the body, you must know that this car was originally painted in light yellow and white, and he looked like a fledgling young man, but now it is covered with mud and sand, the paint and coating are peeling off, and the rough scratches run from the front to the rear of the car, and the young man has also become an old man covered with scars, "From now on, follow the old cat, get out of here, go as far as possible, and travel all over the planet in your lifetime." ”

Tang Yue tied the solar panels with cables, and the stray dog's front dragged the cart, on which were large bags of luggage.

"Tie it up."

Tang Yue pushed the batteries on the cart hard to make sure they wouldn't come loose.

"Say goodbye to Kunlun, silly dog."

The old cat is wearing an indoor spacesuit, sitting on a chair with the glass helmet of the spacesuit in his arms.

It turned its head to look out the window at Tang Yue, back and forth, and quickly packed its luggage for it, Tang Yue went back and forth between the garage and the rover over and over again, pushing the heavy battery board onto the cart.

He's laughing. The old cat whispered, "Should you laugh when you leave?" ”

"Mr. Cat, if he cries goodbye to you...... Mai Dong asked, "will you still go?" ”

"I'm not leaving." The old cat put his helmet on the table and replied without thinking, "But that stupid boy just doesn't cry, for all these days, every time I looked at him, he smiled and told me to get out of here, get out of here, don't stay and die." ”

The old cat clamped his head hard, his forehead hit the table, and it banged, "As long as he leaves a tear in front of me and says don't go to me, I will rush out and dismantle the wheel of the stray dog, pull out the wire of the battery and tear it up and swallow it, but he won't say anything, the kid just smiled and said to me to get out of here, get out of here, don't stay and die." ”

"Damn, did you think he couldn't cry once?"

The old cat slapped the table and cursed.

"I'm a stationmaster, Kunlun stationmaster! Experienced senior assistants and guides of the Mars scientific expedition team, a total of 167 large and small accidents have been solved! Saved the lives of thirteen people! Let a rookie hang in front of me...... I...... I...... I don't want to lose face...... Why......"

The old cat turned his back, his voice trembling and falling intermittently, his shoulders swaying slightly.

"Mr. Cat." Mai Dong was gloomy.

"Miss Mai Dong."

"Huh?"

"Grief is the enemy of humanity." The old cat said something for no reason, "It's also the enemy of cats." ”

"Do cats get sad too?"

"Yes, cats are sad too." The old cat turned his back to Mai Dong, "If the shovel officer is gone, the cat will be very sad and sad, it will wander over and over again in the place where the shovel officer lived, and then jump on the cat climbing frame, holding a small dried fish, and look at the empty room in a daze." ”

Mai Dong hugged Ah Q in her arms, she didn't know how to comfort this sad cat, cats are born lonely and cold creatures like elves, if they are sad, they will fade away and turn into ghosts wandering in the world.

However, most of the fat and short cats of the old cat can't roam, and the orange cat has been expelled from the cat class.

Tang Yue stepped into Kunlun Station with the cold outside, while taking off the Mingguang armor on his body, he was busy all morning, moved the solar cells and RTG into the car, and put the hard disk that stored the history of human civilization on the car, these things should be taken away by the old cat, and could not be destroyed with Kunlun Station.

"Whew...... I'm so tired that I'm finally packing my luggage. Tang Yue poured a large glass of water, "How's the preparation?" Old cat, can you move? ”

The old cat glanced at him, Tang Yue's tone was as normal as ever, as if he was nothing, as if the person who was going to leave was not the old cat but him.

"I'll sit down a little longer."

"You said this three days ago, and you said it three days ago, and you sat down until today, and the comet will fall in a few days." Tang Yue said, "If you sit for one more second, you will walk one second less." ”

"I know what I know."

"You've got a fart count."

"I don't need you to remind me when I'm leaving."

"If I don't remind you that you can sit here until you are old, do you think you are Bodhidharma?"

"Do you believe I'm leaving?"

"You dare?"

"Tang Yue, let me tell you, I am the stationmaster of Kunlun Station in the substantive sense, appointed by the Secretary-General of the United Nations!" The old cat shouted, "You don't have the right to command me to do anything. ”

"The Secretary-General of the United Nations doesn't care about this, his status has no legal effect, don't take a chicken feather as an arrow, the rotating stationmaster of Kunlun Station is the commander of the mission, so the stationmaster is Lao Wang." Tang Yue said, "You are a cat." ”

"What's wrong with the cat?" The old cat glared.

"The problem is that you're still a fake cat."

The old cat was immediately hit with 10,000 critical damage, and Tang Yue's knife stabbed hard and accurately.

"Fake cats are cats too!" The old cat was furious.

"Since it's a cat, you have to be obedient." Tang Yue stepped forward and hugged the old cat's shoulders tightly, and said in a deep voice, "This is the end of the bickering, let's go, old man, let's go quickly, it's too late if you don't leave...... You can't save me, so why struggle? ”

All the words that the old cat was about to yell lost its voice in an instant, and it fell silent.

No matter how the old cat rolled and struggled all over the ground, it couldn't save Tang Yue.

Procrastination doesn't do anything, and the comet will eventually hit the surface of Mars, and no one can change the outcome.

"You're all gone...... What is the point of my existence? ”

"Mai Dong is still there." Tang Yue said, "Protect her." ”

The old cat nodded slowly, hugged Tang Yue tightly, and he and Tang Yue took one last photo in front of the camera, saying that it could be hung on the front of the car to ward off evil spirits, and Mai Dong also took a selfie and sent it to the old cat, saying that it was a souvenir.

The old cat took a step back, put his legs together, stood upright, and raised his paws in salute.

"Comrade Tang Yue, Comrade Mai Dong, job title number UNMEP360037A senior assistant and guide commissioner of the Mars landing program, say goodbye to you! Treasure all the way! ”

Tang Yue and Mai Dong held back the expressions on their faces and raised their hands to return the salute.

"Comrade Cat, Job Title Number CNMEP390012C Mars Landing Program Payload Expert, Mechanical and Electrical Engineer Tang Yue, say goodbye to you! Treasure all the way! ”

"Comrade Cat, Job Title Number CNMEP390022C Mars Landing Program Payload Specialist, Plant and Agroecology Technician Mai Dong, Farewell! Treasure all the way! ”

The old cat put on his helmet, took one last look at Tang Yue and Mai Dong, and turned to step into the hatch of the airlock room.

With a "click", the hatch slammed shut.

The old cat is gone.

It will not come back.

The seriousness and calmness that Tang Yue had forcibly maintained collapsed instantly, and he stepped back step by step and sat down on the chair.

"Tang Yue, aren't you going to send Mr. Cat?"

Tang Yue turned his back to Mai Dong and shook his head.

"Mai Dong, do you know why I can't go out? Cause...... Because I'm afraid I'll chase me out...... It...... And it goes...... Can't walk......"

"Is it because Mr. Cat doesn't want to go?"

"Yes...... It's me, I'm ...... I don't want to...... Let it go. ”

·

·

·

Five minutes later.

With a "click", the old cat pushed open the hatch of the airlock chamber, and it actually came back.

Tang Yue and Mai Dong were both taken aback, and at the same time, they were overjoyed, and they had the feeling that Uncle Liu Huang would return when he saw Xu Yuan go straight away.

"What are you doing here?"

The old cat looked solemn and hurried, with a body of wind and sand, did not answer Tang Yue's question, and did not even greet Tang Yue Mai Dong, it didn't even have time to take off the spacesuit on its body, sat straight in front of the table, and turned on the computer.

The old cat pulls up a photo from the computer, the young girl is facing the camera, wearing blue overalls, wearing a peaked cap, smiling, as if it were a ID photo, with the control panel and various monitors in the background - this is obviously the selfie that Mai Dong has just sent to the old cat.

She originally wanted to shoot a little more playful, but she was really not in the mood when she parted.

"Miss Mai Dong! Can you hear me? Miss Mai Dong! ”

"Mr. Cat...... What's wrong? ”

"Wait, wait, don't speak, don't talk yet...... Here's the picture you just sent me, right? Here's the selfie you just sent me! The old cat's voice was trembling, and the paws of its mouse-holding were also trembling, and Tang Yue and Mai Dong both realized that something was unusual.

"Yes."

The old cat framed a screen in the background of the girl's photo, which was a dark starry sky that appeared blurry on the photo, presumably an observation from a space station telescope.

"Miss Mai Dong! Is this display the star-finding system of the Survey Telescope on the United Space Station? ”

Mai Dong didn't know why, and nodded.

"You had the telescope track that comet all the time?"

"Yes."

"Old cat?" Tang Yue was confused.

"Shut up! Don't talk! Don't interrupt me. The old cat snorted, staring at the picture on the monitor, "Miss Mai Dong, in this photo of yours, can you see how many celestial objects are approaching you?" ”

"In this picture, how many celestial bodies are moving towards me?" Mai Dong didn't understand why the old cat asked this, she opened her laptop and called up the observation data of the survey telescope again, "Isn't it obvious, there is only one, and that is the Tomcat-Tang-Mai comet...... Wait, what's that? ”

Mai Dong's last question surprised Tang Yue, who was listening, he didn't know what was going on, but it was obvious that something unusual had happened.

"yes, how did it get here? At this time, it shouldn't have been in that position! How is this possible? It's not in its tracks! The old cat trembled slightly with excitement, and slammed the table with both fists, "Impossible, impossible, impossible, impossible, this is completely impossible!" It's impossible！ ”

"What the hell are you talking about?" Tang Yue leaned over.

The old cat turned the computer screen over and showed Tang Yue the complete observation photo, which at first glance looked no different from the other photos of the space station's survey telescope. The old cat pointed to a bright spot on the left side of the photo, the halo was clearly visible under the lens of the telescope, and asked, "Do you know what this is?"

"Comet?"

The old cat nodded, and it moved its toes slightly, "And what about this?" ”

Tang Yue was stunned, and after looking closely, he found that there was another bright point of light in the comet's halo, what was going on? This is also the nucleus of a comet? Comet Tomcat has two comet nuclei?

"This ...... Also the nucleus of a comet? ”

"Nope." The old cat shook his head, "That's not the comet nucleus, it's not actually inside the comet, it's just that the two are squeezed together because of the shooting angle......"

The old cat paused.

"That's Demos."

·

·

·

Phobos, Demos.

It is the smallest moon in the solar system, more than 23,000 kilometers from the surface of Mars, more than 12 kilometers in diameter, in Greek mythology, Deimos is the son of Ares, the god of war and Aphrodite, the god of love, this small moon orbits Mars at 1.35 kilometers per second, and it takes more than 30 hours to complete a revolution cycle.

Because it is so small, its presence is extremely low, and occasionally Mai Dong can find that small bright spot passing in the deep sky 20,000 kilometers away, extremely inconspicuous against the background of bright stars.

"I don't know why it's here, the orbital inclination of Demos is 0.93° and the eccentricity is 1.79! This is completely off its track, how did this guy fly here? It simply can't and shouldn't be here! The old cat tapped frantically on the keyboard, "This satellite has been operating peacefully in its orbit for billions of years, why did it suddenly change?" ”

The workstation is running at full capacity, and a huge amount of data is being transmitted from the space station.

The old cat jumped impatiently while muttering about the impossible, the impossible, the totally impossible.

It was building a model, a model that accurately predicted and simulated the trajectory of a comet, and Tang Yue and Mai Dong were watching nervously.

"We've never considered Deimos before, because its orbit is not on the same plane as the comet, and the cycle is not right, so this little guy should hide on the far side of Mars to cool off when the comet hits the surface!" The old cat was very excited, and his voice was as fast as a machine gun, "This is what humans have observed in the past hundred years, and nothing has changed!" ”

"But observations from the Joint Space Station and photos of Miss Maidon have just told me that its orbit has changed...... Hell, this guy is off the rails! How is this possible? A behemoth weighing 1.8×10∧12 tons, who can easily change its orbit? Who can drive 1.8 trillion tons of mass? Could it really be that some unknowable force is pushing it in the dark? Or is there something wrong with Mars itself? No...... Not right......"

The old cat muttered to himself, shocked by his own speculation.

All the clues converge in its brain, interlocking, and finally come to the answer.

Its eyes widened slowly.

Not some unknowable force.

Nor Mars.

"The celestial body of the solar system is a chaotic system, there are too many influencing factors, it is impossible to predict accurately, and it affects the whole body, and there is a 600 trillion trillion tons of things that suddenly disappear for no reason 100 million kilometers away, so the orbit of this little thing has been affected, and in front of the real giant of the earth, Phobos is too small and too light, so the impact results are quickly revealed......"

Tang Yue and Mai Dong were already stunned.

Neither of them dared to speak, for fear of disrupting the old cat's train of thought, and it rushed back in less than five minutes after going out, surely for something very important.

The mathematical model is built.

The old cat hit the enter key hard.

The code went off, the computer screen went dark, the comet's trajectory was indicated by a blue line, and Mars was still a large red circle — at this distance, the Kunlun station computer was able to predict the comet's path with great precision.

"Tang Yue! Miss Mai Dong! ”

"Huh?"

"Huh?"

"Let's roll the dice, do you think we can roll a six?" The old cat asked.

The comet Tomcat on the screen moves slowly, drawing a blue arc.

"What is the probability of a six?" Tang Yue asked.

"It's small, it's small, it's smaller than the probability of a comet hitting Mars." The old cat replied.

Tang Yue smiled.

"The problem is that the comet is already hitting Mars."

"Yes." The old cat nodded and grinned, "The comet is already about to hit Mars." ”

At that moment, Tang Yue raised his head, he could feel that there was some kind of powerful force and oppression in the distant deep space coming straight towards him, there had never been such a moment, Tang Yue could perceive the existence of Tomcat's comet so clearly, as if someone had opened his God's perspective, he could see the huge comet nucleus tumbling and evaporating in the deep space, dragging a thin tail of water vapor and carbon dioxide.

Tang Yue suddenly understood why some people believed in mechanical fatalism, the universe was a huge machine, the solar system was a flywheel, and Mars was the gear on the flywheel, and the comet was a crankshaft or connecting rod that moved back and forth, everything was running precisely. Think of Ptolemy's geocentric theory, the planetary rotation is the structure of the same round on the top of the wheel, one round after the other, just like the gears that bite each other, this seemingly complex theory in the deepest and lowest layer actually embodies the most concise and simple mechanical mathematics.

Will Demos save their lives?

Tang Yue didn't know either.

"Throw it boldly!"

The large blue spiral gradually approached Mars on the screen, and the result was exactly as predicted by the workstation, and it would fall on the Great Setis Plateau, destroying everything.

Tang Yue clenched his fists.

Mai Dong hugged Ah Q in his arms.

Suddenly a white line appeared on the edge of the screen, and it was the orbit of another celestial body! Tiny Demos has burst into the spotlight - the old cat had never included Deimos in the previous calculations and predictions, because it was excluded from the first place, and satellites in fixed orbits were the best way to predict position, and based on the available information, it only took a second for the computer to deduce that it had no effect on the comet.

Demos has been orbiting it for billions of years, and no one knows that it has quietly changed places.

Deimos was flying much slower than Comet Tomcat, but the white orbit was still stretching unhurriedly, and even the blind could tell that it would stop right in front of the comet if it flew like this.

Tang Yue pinched the old cat's shoulder, and the old cat pressed his paw on the back of the former's hand, signaling him to calm down, but the old cat couldn't calm down himself, and his legs under the table trembled like chaff.

The two people and a cat are staring at the two lines on the monitor, this will be the scene of a space car accident, Tomcat Comet is a heavy-duty truck that has soared to seventy miles, uncontrolled, God blocks and kills, and is crashing head-on into the residential area across the road, and Demos is an ignorant Chery QQ, which is slowly driving from the intersection, whether the two people and one cat in the residential area can be saved, it depends on whether this Chery QQ can crash into the Mercedes-Benz truck.

This possibility is another comet hitting Mars, except that Comet Tomcat has become the victim of the collision.

Bump it bang it!

Bang it hard!

Hit it hard——!

Tang Yue clenched his fists, his face was flushed, just like a spectator watching the game on the field, in the case of the two sides equalizing the score, there was still half a minute before the end of the game, but our players had already broken through the enemy's defense with the ball, entered the enemy's penalty area, kicked this goal, and the success of the shot was a lore!

Mai Dong buried his face in Ah Q's stomach and didn't dare to look at it anymore.

Tang Yue didn't know how long it was, it might just be a dozen seconds, it could be a few hours, or even a long time like a year or even a lifetime, the moment the two tracks intersected, "drop-" sounded, a large amount of data burst out, and a red pop-up window jumped out.

IMPACT！

In the moments before the end of the game, your player kicked that goal hard!

Lore!

Within two seconds of the impact, the computer gave the result, and the Chery QQ of Demos caught up from the side and back, and inserted a pole horizontally - to be honest, Demos was also very dazed and innocent, and he didn't know why he was hit by such a behemoth, which was really a miracle. Comet Tomcat collided with Phobos at a very small angle, and the result of the collision was a change in the orbits of both sides, similar to two billiard balls colliding, with momentum conserved and both changing the direction of velocity at the same time.

Demos was pushed so hard that the orbit became a large flat ellipse, and the nucleus of Comet Tomcat was reacted away from Mars, and its closest approach to Mars would rise to more than 10,000 kilometers, passing by Mars.

The old cat pushed away the computer and chair vigorously, turned around and hugged Tang Yue tightly.

"Hahaha Miss Tang Yue Maidong, we can live! Hahahaha! ”

"Hahahahaha! Hahaha we can live! I can live! Mai Dong, we can live! ”

A man and a cat hugged each other and cried and laughed, jumped and jumped.

·

·

·

Half a month later.

When Comet Tomcat-Tang-Mai collided with Demos, it was a sunny day on the Kunlun station, and the United Space Station was located on the far side of Mars, and just in case, the space station had all the solar sail panels and heat sinks folded away to prevent the debris from the impact from posing a threat - in fact, the space crash happened 23,000 kilometers away, and the debris produced is unlikely to threaten the space station.

The old cat observed with a telescope and found that there were far fewer debris than he had imagined, after all, Deimos and the comet did not collide head-on, but obliquely grazed, and Demos was a large rock with a diameter of twelve kilometers, much denser and harder than a loose comet nucleus, and this time the impact was an egg against the stone - but the larger one was the egg.

The main components of Comet Tomcat are water, methane and dry ice, which evaporates quickly when exposed to sunlight.

If the wicked really need the wicked to grind, such a huge celestial body as Comet Tomcat, human beings can't handle it, so they can only leave it to God to clean up.

The space station and the Orion spacecraft are ants and whales to comets, but Demos is another whale, and only whales can shake whales.

Night falls.

Tang Yue and the old cat went out to see the comet.

Comet Tomcat-Tang-Mai tripped over a stone on the doorstep of Mars, which saved Tang Yue's life and his own, and the comet passed Mars at an extremely close distance, and then crossed the Martian orbit at a speed of more than 60 kilometers per second and continued towards the Sun.

Tang Yue was fortunate to see the most spectacular comet of this century, except for the probe, human history has never seen a comet at such a close distance, it dragged two long comets, the light almost across the entire sky, the evaporated gas of the comet is ionized in the solar wind, emitting blue and red light, like the skirt of the goddess.

At this moment, there is nothing in the world that can overpower her brilliance and beauty, she is the most dazzling girl on the dance floor, attracting the eyes of the audience.

"Strictly speaking, we're in the interior of the comet right now." The old cat leaned against the wall of Kunlun Station, sat on the sand, and said leisurely, "The comet's head is more than 100,000 kilometers in diameter and its tail is millions of kilometers long. ”

Tang Yue sat beside the old cat and looked up at the comet under the canopy.

"How long will it stay here?"

"Comet Tomcat's orbit is parabolic, and it will stay inside the orbit of Mars for more than a month, and then leave the other side of the solar system and never return."

"Aren't you coming back?"

"Not coming back."

"It's a pity and regret...... Tang Yue pillowed his arm, "I think." ”

"What a pity?"

"It's a comet that we named ourselves, and we have been to the solar system, which shows that we have a fate with it, and we have a fate to meet thousands of miles away, it is not easy to have a fate with something in this huge universe, and it would be good if it could come back to see us in the future, even if we are no longer there."

Tang Yue felt that he had formed some kind of connection with the comet that almost destroyed everything, this connection was ethereal, just because it had been to the solar system, just because you had made a name for it, but even such a fragile connection was extremely precious in the vast universe, so precious that you could ignore hatred and sorrow and easily reconcile with it.

"Your fortune-telling skills haven't arrived home yet." The old cat said suddenly.

Tang Yue was stunned.

"The last time you counted the hexagram, the hexagram was not helped, and you said that the meaning of the bad luck was a great omen." The old cat said, "In fact, the meaning of the end of the road is not the end of the road, but the matter is not over, there is still hope in the despair, and there are still willows and flowers after the end of the road...... The cuttlefish fairy in your hometown likes to eat cuttlefish, and you always give squid to others, so it's obvious that people don't teach you real kung fu. ”

Tang Yue was taken aback.

"Really?"

The old cat nodded.

"But none of that matters anymore." Tang Yue stood up and walked towards the desert, then stood under the starry sky and waved his hands, shouting towards the comet that was gradually moving away: "Hey——! Goodbye——! Bon voyage! Goodbye——! ”

"Goodbye——!"

The old cat sat lazily, it looked at the young man waving goodbye to the comet under the stars in the distance, Tang Yue's small back fell in the eyes of the old cat, he stood alone on the sand dunes and talked to the universe, the old cat didn't know whether Tang Yue's body was shining at this time, or the light of human nature and divinity.

Suddenly, there was a rain of meteors overhead.