ps: Thank you readers for voting for a monthly ticket to heaven "Qingming Valley Rain", thank you, thank you ^_^ for the reader "zgynkmzty", "Big Brother Flying Dragon", "Zizhu" respectively rewarded Heaven 100 vertical and horizontal coins, thank_you^_^, looking at the increase in monthly tickets and rewards, a sense of affirmation and satisfaction rose from the bottom of my heart, Heaven was very excited and happy o(∩_∩)o haha~

Main plane: Central Pacific Hawaii, Mount Mona Kea Observatory. Perched atop Mount Mona Kea in the Hawaiian Islands, it is one of the world's most famous celestial research sites and is recognized as one of the best observatories in the world.

Due to its good visibility, low humidity, clean air and close proximity to the equator, the Mauna Kea is an ideal astronomical base. At the Mauna Kea Mountain Observatory, you can see a variety of telescopes established by various countries and institutions, and large professional telescopes are scattered all over the top of the mountain, which is very spectacular. This world-class astronomical research observatory consists of 13 observatories, such as the Infrared Telescope (IRTF) of the Stars and Stripes Republic, the Canada-France-Hawaii Telescope (CFHT), and the Uqko National Astronomical Observatory Telescope.

Clark is a Canadian astronomy enthusiast who became a CFHT Observatory staff member after graduating from college and has been living and working in Hawaii for 17 years. Usually, when the night sky falls, he runs to the top of the mountain alone and looks at the starry sky with his astronomical equipment or borrowed a telescope from the CFHT, enjoying the magnificence of the universe.

Every year from November 14rì to 21rì, especially around November 17rì, some meteors burst out from the direction of the constellation Leo, which is the famous Leonid meteor shower. The famous "Leonid" meteor shower is not actually a meteor shower on the "Leoid", but is formed by particles thrown by a comet called "Temple Tatel" that slides through the atmosphere. Because the orientation of the meteor shower is formed, the projection on the celestial sphere coincides with the projection of the "Leo" on the celestial sphere, so it looks as if the meteor shower is sprayed from the "Leo" constellation on the earth, so it is called the "Leonid" meteor shower.

"It's good that it's almost time for the Leo 'Meteor Storm' to break out again!" Clark fiddled with the equipment in his hand and couldn't help but say (the cycle of Leonid meteorstorms is once every 33 years, the last time was 2001, and this is for the plot to need to pull Lang match, please forgive me).

"Hey, Clark, what's in your mouth?" Clark's temporary colleague, Humboldt, asked curiously. Humboldt, a German, 15 years younger than Clark and 24 years old, came to CFHT for a professional internship as a master's student.

"Hehe, Humboldt, I'm looking forward to the Leo 'meteor storm' in 2 months!" Clark replied with a smile.

"Actually, I'm scared of the 'meteor storm' every time." To Clark's surprise, Humboldt said unnaturally.

"What's wrong?"

"Aren't you worried that they will break through the atmosphere and destroy the only home for humanity?"

"Wowhaha, Humboldt, you're worrying too much!" Clark knew that Humboldt's specialty was optical imaging, and the correlation with the sky was not very high, so he explained with a smile: "Meteor showers originate from the friction between meteor swarms and the earth's atmosphere, and meteor swarms are because of the comets on the way, scattered particles of material or disintegrated comet nuclei, but you don't have to worry too much, these fragments and hui nuclei are very small, basically less than 1mm, and they are burned by friction when they enter the atmosphere, and the historical record of damage to meteor showers themselves is only to kill a few sheep in Brazil in 1836, The killing of a dog in Egypt in 1911, the Australian meteorite that pierced the roof in 1969, and so on, are much less harmful than the annual traffic accidents! ”

"But I'm afraid of catching up with a meteor big enough, you must know that the dinosaurs are likely to be extinct because of the meteor hitting the earth!" Humboldt remembered the historical inferences he had seen when he looked up materials in the library and worried.

"This is really possible~~" Clark saw Humboldt's appearance, and answered with some amusement: "But think about it, it may be millions, tens of millions, or even hundreds of millions of years later, the real small probability event, maybe when human civilization rushes out of the earth or perishes, the meteor has not yet approached the earth!" ”

"Hope you're always right!" Humboldt, who is pessimistic for the majority of the xìng grid, reluctantly agrees.

"Okay, let's ~~~" Clark just wanted to say go for a drink.

"Dingding!!dingding" The computer that was analyzing the data suddenly rang.

"What's wrong?"

"It's okay, it's the celestial orbit calculation software, wait a minute, let me see what's going on!" Clark replied without a heartfelt response.

Five minutes later, Clark's expression had gone from relaxed to slightly solemn.

"Humboldt, let me ask you, did you enter the new CFHT photograph into it?"

"yes, as usual, I put the photos I take every day in the photo gallery, what's wrong?"

"Weird? According to the latest photographs taken there in the constellation Leo, a new comet has appeared there. ”

"Did Temple Tattle come back early?" Historically, the interval between meteor showers has varied, earlier or later, so Humboldt replied unconcernedly.

"That's what I thought at first, but," Clark said, frowning more and more.

"What's wrong? But what? ”

"I just roughly measured the size of this comet, it is more than 1,500 times larger than the volume of 'Temple Tartl', and the computer estimates that its orbit is more than 80% similar to that of Temple Tartl!" Clark explained.

"More than 1500 times? 80% similarity? ”

"yes, looks like I need to give the professor a call." As he spoke, Clark picked up the black sè landline on the table and pressed the button, "Hello, Professor Stephen?" I'm Clark, we've found something unusual here, can you come over and take a look? ”

An hour later, Professor Stephen, Clarke, and Humboldt, who rushed to the observatory, carefully recalculated the volume and orbit of the unknown comet.

"Clark, we may be in big trouble, hopefully our calculations are wrong!" Professor Stephen, who had white hair, said with an ugly face.

"Professor, why don't we bring people from other observatories over and review our calculations together." Clark was reluctant to accept realistic advice.

"Okay, Humboldt, can you please call them?"

"Okay, I'll go!"

Three hours later, the Mount Mauna Kea Observatory and the Canada-France-Hawaii Telescope (CFHT) were crowded with astronomical staff from other countries.

"Professor Stephen, we've done the math five times, and there's no mistake, this unknown comet will pass near the Earth like Halley's moon, it's just," Professor Raul of the Stars and Stripes said, with an equally ugly face.

"According to the estimation of past comet data, the volume of this unknown 'Comet X' is more than 1,500 times that of 'Temple Tartl', and the particles and nuclei it releases are probably at least 100,000 times that of 'Temple Tartl'." Professor Waltie of Australia replied, "According to the meteor burst recorded by Eggers, an astronomer living in the suburbs of Boston, on November 13, 1833, it was an average of 580 meteors per minute, and an estimated 35,000 meteors per hour, for a total of about 240,000 meteors. Then 100,000 times is 24 billion. ”

"24 billion, although the number sounds scary, but if they are all less than 1mm, it is not a concern, but according to the general statistical law, one in every million meteors will break through the atmosphere, that is, about 24,000 will break through the atmosphere this time!" Professor Stephen replied with dry lips.

"Are we going to be as extinct as the dinosaurs?" Humboldt asked nervously.

"No, Humboldt, although there are more than 24,000 or even nearly 30,000 of them, they are small in size and do not stir up huge amounts of dust that will flood into the atmosphere to block out the sunlight, and the dinosaurs are presumed to have an asteroid with a diameter of more than a kilometer directly hitting the Earth. This is more than 90% of the fragments, which will only be the level of dust that breaks through the roof, and as for the remaining 2400~3000 grains, according to the calculation model results, most of them will also be the threat of hitting out of the potholes the size of the sink, only the last one percent to one thousandth," Professor Stephen said, and finally his voice was quieter.

"What's wrong with one percent to one thousandth?"

"That is, about 24 to 300 out of 24,000, which will pose a relatively big threat to us!" Professor Raul chimed in.

"How much of a threat? Professor! Clark asked nervously.

"Preliminary estimates may have the power of an ordinary artillery shell to two or three hundred thousand tons of TNT explosion." Professor Raul replied, "The most troubling thing is that we don't know exactly where they fell at this time. ”

"Oh my God!!"

"I suggest that we report to each other, and now we need more experts, including mathematicians, to get involved and make more accurate calculations of the analytical model!" Professor Stephen suggested.

"I agree!"

"I agree!"

A few hours later, the heads of the world's major countries all received urgent documents about the sudden meteor storm.

The Star-Spangled White House, Obama and a group of thinkers, including invited astronomical experts, convened an emergency meeting.

"Gentlemen, we're in big trouble!" Obama, who had a serious expression, did not talk nonsense, and said straightforwardly: "Next, Professor Raul, give us a specific explanation." ”

"Ahem, gentlemen, yes, this year's Leonid meteor burst was unexpected," Professor Raul began to explain in detail.

Half an hour later.

"Professor Raul, do you estimate that 24 to 300 nuclear bombs or small nuclear bombs will fall on Earth? Do you know what that means? The Minister of National Defense, Chuck Hagel, said with a frown.

"I know, but I need to be reminded that first of all, they are not nuclear bombs in the true sense of the word, that is, they will not produce lethal long-term nuclear radiation, and secondly, the estimated about 300 threatening comet fragments, most of which are just the destructive power of ordinary artillery shells, it is estimated that the fragments of more than 1000 tons of TNT bombs account for only 40%, that is, about 100~120 pieces!"

"How many will our country suffer?" Rice was not polite and asked.

"Because 70% of the earth's surface area is ocean, there are only about 30 to 40 of them that have landed on land, because our land area is relatively large, it will be about 4, according to our repeated calculations, there will be one of them with a power of about 200,000 tons of TNT, a power of about 50,000 tons of TNT, and the remaining 2 will be roughly between 5,000 and 10,000 TNT." Professor Raul replied.

"Hagel, can our national missile defense system shoot them down?" Obama looked hopefully at the Secretary of Defense.

"It's hard to say." "They will eventually descend on the ground at a speed of more than Mach 100, and it is impossible to catch up with them from behind with interceptor missiles, and in order to destroy them in the air, they must be hit directly from below, or from the lower side, and then detonate the missile to counteract the terrible kinetic energy it carries, in this case, we need to do at least two things!" ”

"Which two?" Hillary asked hopefully.

"First, a sufficient number of missile launchers should be assembled at the landing site to ensure that no matter which direction the target enters, there will be interceptor missiles on its relatively vertical ground that can be fired. Second, it is necessary to equip a sufficient number of phased array radars, because the speed of comet fragmentation is too fast, and the error must be controlled within 1/100,000th of a second! ”

"What do you mean?" Obama didn't get it.

"I'm afraid we need to bring back all the Patriot hair units and pre-jǐng planes at various bases around the world, just like that, those countries will probably be," Defense Secretary Chuck Hagel said, the quieter his voice became.

Half a minute later.

"Call them all back!" Obama decided.

"Your Excellency, then our relations with the countries of Europe, the Japanese in Asia, South Korea and other countries will immediately fall to the freezing point, forming a huge and irreparable rift, because we have abandoned them at the critical moment! After all, it's just 4 threatening comet particles. If the landing site is deserted and inhabited, the economic loss is very small and can still be bearable, does this do more harm than good? Hillary Clinton reminded.

"Professor Raul, have you calculated the landing site?" Obama asked.

"Not yet, but," Professor Raul said.

"Say!"

"More than 80% of the debris of the comet, which has a destructive power of more than 200,000 tons of TNT, will land on the east coast." Professor Raul's voice grew smaller and quieter as he spoke.

"I see, thank you!" Obama nodded solemnly, then said loudly, "Chuck Hagel!" ”

"Yes, Your Excellency!"

"I now order, in the name of the president, to transfer back to the country all the Patriot defense missiles and pre-jǐng planes that we have scattered around the world, all of them, not one of them will be left, understand?"

"Yes, Your Excellency!"

"Your Excellency, please," Hillary Clinton said again, reluctantly.

"Enough! I want to reiterate that we must take the national interests of the Stars and Stripes as the first priority, take back all Patriot missiles and pre-jǐng aircraft, intercept the comet fragments, and as for those allies, I believe that as long as our military and economic strength is not damaged, they will obediently give in again! Do you understand? ”

"Understood!"

"Yes, Your Excellency!"