"Comet?" Tang Yue was taken aback.
Mai Dong was installing the C1002 circuit when she heard what Old Cat said. She looked up and asked, "Is it the comet from Halley's Comet?"
"Yes, it's the jinx."
Old Cat replied, "But it's not Halley's Comet. This is a new comet. There are no records of it in history. It's an aperiodic comet with a hyperbolic orbit."
"When did you discover it?" Tang Yue was a little surprised.
"Just now. I just confirmed its existence."
Old Cat pulled up the observation data on a monitor. "Because this star has brightened seven times in the past forty-eight hours, its apparent magnitude has suddenly increased from six to four. I originally thought it was a variable star, but later I found out that it's a celestial body in the solar system. The rapid increase in brightness is because it's rapidly approaching the sun."
"Does that mean we can see the comet?" Mai Dong was pleasantly surprised.
"What does this mean?"
Tang Yue's reaction was very nervous. The first thing he thought of was an asteroid hitting Earth. "There won't be any danger, right?"
"The situation is not clear for the time being. I've turned on the survey telescope on the space station and prepared to track it. Soon, I'll be able to predict its orbit."
Old Cat replied, "Based on the current results, this is a comet that has never been to the solar system. Its origin might be the Oort cloud …"
"Who cares where it comes from? As long as it doesn't come to Mars," Tang Yue mumbled.
"Can I see it?" Mai Dong asked.
"Yes, Miss Mai Dong."
Old Cat said, "But its current brightness is not higher than most stars in the night sky. However, as time passes and it gets closer to the sun, the comet's apparent magnitude will continue to increase."
Mai Dong straightened up and looked around. The stars in the sky were shining brightly, but she couldn't find the broom-like comet she had imagined.
"But I can't find it. Isn't the comet a big broom?"
"It's not close enough to the sun, so the comet tail isn't obvious, but it won't be long before you find it. This is a rare comet, and its comet head should be more than two hundred and eighty thousand kilometers in diameter." Old Cat said, "Do you know what this size means?"
Mai Dong shook her head.
"Jupiter's diameter is only 140,000 kilometers, but its diameter is twice that of Jupiter."
"When Comet Tomcat-Tang-Mai I is closest to the Sun, it will become the brightest star in the entire sky. It will also leave a massive comet tail that's more than a hundred million kilometers long as it sweeps across the entire night sky."
"Wait, wait, wait, what did you just say?
What's Tomcat-Tang-Mai? "Tang Yue frowned. Old Cat rarely spoke human words.
"The name of that comet," the Old Cat replied.
"You said before that this was a new comet that had never been recorded."
"Yes, so I just named it." Old Cat nodded. "According to the rules of the International Astronomical Union, comets are named by the person who discovered them."
Tang Yue chewed on the name a few times before realizing that Old Cat had named it after the three of them.
Comet Old Cat Tomcat-Tang-Mai I.
This was probably the last comet in human history to be discovered and named.
"How long will it take for you to confirm its orbit?" Tang Yue asked.
"The space station's telescope is tracking it, and the prediction will be out in a few days. What we can confirm now is that this comet will definitely enter the original Earth's orbit, which means that it will pass by the orbit of Mars, but we don't know if it will brush past Mars."
Old Cat replied, "But you don't have to worry about any problems. Although the comet is a celestial body that looks frighteningly large, 99% of its composition is thin gas. The real solid nucleus is only a few dozen kilometers in diameter."
"In other words, it's impossible for it to hit Mars?" Tang Yue asked.
"Impossible. The comet's flying speed is too high, far exceeding the speed of all the planets in the Solar System. Unless Comet Tomcat-Tang-Mai I plunges into the Roche limit of the two and is directly torn apart by tidal forces, Mars has no ability to capture it." Old Cat shook its head.
"We can do a simple calculation. The main component of the comet's nucleus is water, so its density is similar to ice. The average density of Mars is very low, about four grams per cubic centimeter. According to the fluid Roche limit formula, d = 2.44R ³ √ (ρ M ρ m), we can get a result of 7004 kilometers.
"In other words, this comet has to be at least within 3,600 kilometers of the surface of Mars before it can be torn into pieces and then smashed to the surface of Mars … I'm not telling you this information to make you worry, but to make you pay attention when the time comes."
Old Cat continued, "This comet may become the brightest celestial body in this century. It's a rare astronomical wonder."
Tang Yue breathed a sigh of relief.
He would rather not see this nuisance of a celestial spectacle than get into any trouble.
Old Cat suddenly told him that at this time, there was a celestial body rushing toward Mars' orbit at a high speed of seventy to eighty kilometers per second. This kind of news would make anyone's heart skip a beat.
In Mai Dong's eyes, this was a romantic thing.
But in Tang Yue's eyes, this was simply a nuclear strike warning.
"As long as something like Shoemaker Levy 9 doesn't happen. Old Cat, you have to know that humans are naturally afraid of celestial bodies like this. After all, our ancestors were creatures that survived such a nuclear strike in space. If it weren't for the asteroid that fell into the Gulf of Mexico 65 million years ago, I might have a lizard face now."
Tang Yue said, "I don't care about the wonders. I've seen the wonders of the Earth disappearing. What else can surprise me?"
"It was Jupiter that tore Shoemaker apart." Old Cat said, "Compared to Jupiter, Mars is still too far away."
"Why did a comet suddenly come at this time?" Mai Dong asked as she turned the screw.
"It's not that sudden. We just discovered it."
Old Cat replied, "When it passed the orbits of Neptune and Uranus, because it was too far away, it hardly emitted any light, so we couldn't observe it. In fact, it has already entered the solar system."
"Will it come again in the future?"
"No."
Old Cat said, "This is a wandering comet. After leaving, it will never come back. In fact, most comets are like this. They drift around, are pulled by the gravity of the sun, turn around and leave, and never come back."
"Wandering … Wandering."
Mai Dong said softly, turned the last screw, and finished installing the C1002 circuit. "Where did you come from?
Where is the way back? "
She looked around again, trying to find the wandering celestial body that broke into the solar system.
But as Old Cat said, the comet's brightness was too low at this time. It was like a drop of water hidden in the boundless sea of stars.
This was an ancient starry sky.
The youngest light that fell into the girl's eyes was from four years ago.