"Hello everyone and welcome to Planet Exploration." Deng Weiwei tried to pretend to smile brightly at the camera, "Some people depict meteor meteorites as silver light leaking out of God's garden, saying that they fall to the ground and shatter into beauty. It's a beautiful description, but in reality, the damage caused by the meteorite falling to the ground is enormous. ”

"Today we are in the fiery crater of the state of Luonaka in the Federation of Madda. The indigenous people who have lived here for generations have many legends about this large pit. But it wasn't until 400 years ago that the existence of the crater was first reported. ”

Deng Weiwei turned around, his eyes also looked at the giant pit behind him, the director waved his hand, and the strong man carrying the camera moved towards the pit with steady steps, and the camera naturally moved away from the host's body and aimed at the pit that was more than 200 meters deep.

But Deng Weiwei ran to the old man who was half-squatting on the ground, and then the director's gesture changed, and the camera switched back to the host. She smiled and said, "Today we are fortunate to have Professor Wu Zhongda, a famous planetary physicist from Ghriss, to tell us an interesting story about this crater. ”

The camera focused on the old man, who grinned, and the wrinkles on his face deepened.

Deng Weiwei did not stop narrating: "Hello, Professor Wu! Welcome to our program. ”

After speaking, he stretched out the microphone to Wu Zhongda.

Wu Zhongda seemed to be a little unaccustomed to talking into the long microphone, but he still slowly got used to it: "Hello everyone! I'm Wu Zhongda, and I'm excited to meet you on Planet Exploration. ”

"Professor Wu, can you tell us about the origin of this crater?" Deng Weiwei put the microphone into his mouth and asked a word, and then stretched out to Wu Zhongda.

Wu Zhongda said: "This crater was formed very early, and about the humans there are still living on the earth. And did not move to the planet Glis. At least 50,000 years ago, it was a plain as far as the eye could see. Until one day a bright star appeared in the north. Run at a very fast speed to the planet Gris. Mixed with a deafening sound and dazzling white light, it slammed down on the ground in front of it at speeds of up to 90,000 kilometers per hour. ”

Deng Weiwei showed extreme surprise, what kind of speed 90,000 kilometers is unimaginable.

"This meteorite, composed mainly of iron and nickel, is less than 20 meters in diameter and weighs as much as a million tons, and with such a large mass and such a high speed, the impact is more powerful than any dark matter explosion in human history. All the trees and creatures in a radius of tens of kilometers in this area were not spared, and the energy of the impact moved about 600 million tons of stones. Extrusion and accumulation formed a high convex part of the crater's edge. ”

"So powerful?" Deng Weiwei was so surprised that he took a breath.

"Yes, think about it...... Wu Zhongda said, pointing to the huge crater behind him, "This meteorite with a shape close to a perfect circle is less than twenty meters in diameter, while its impact crater is three kilometers in diameter, so big enough to play fifty ball games at the same time. The depth is equivalent to seventy floors. To put it in layman's terms, it's the equivalent of punching a bullet into a bunker. ”

"Professor Wu, I heard that there are many interesting things about this crater, can you tell us about it?" Deng Weiwei asked enthusiastically.

"At the beginning of the discovery, almost everyone thought it was just a crater caused by a volcanic eruption, after all, there were many large and small volcanic cones scattered across this endless plain. But as more and more geologists came to explore, fragments of ferrous meteorites were collected around the crater. It was only then that people came to believe that this geographical wonder was actually hit by a meteorite that flew from the sky. Wu Zhongda said.

Deng Weiwei then asked: "I believe that the first problem that everyone has when they see this large crater is the meteorite that caused the impact in the first place. Where are you now? Professor Wu, did you just say that this meteorite has been completely shattered and scattered around? ”

Wu Zhongda shook his hand and said with a smile: "Not exactly, three centuries ago, many people spent a lot of time digging down from the bottom of this crater, hoping to dig deep to find more, but in the end it was in vain. It wasn't until someone came up with a theory that even if the meteorite was incident obliquely, it would produce such a circular crater, and everyone looked at the terrain around the crater and found that the terrain on its southern edge was particularly prominent, very different from the other parts, so he concluded that the meteorite was obliquely shot down from the northern sky and buried deep in the southern mountain wall. ”

"In the south side of the mountain? Such a big piece of iron, why not dig it out? Deng Weiwei asked again.

"After proposing this theory, people formed an excavation team to dig into the mountain wall on the southern edge, but when they dug more than 1,000 meters, they came across something extremely hard, and so far no man-made machine has been able to go any further, and it is believed that this is where the meteorite was buried." Wu Zhongda sighed and looked down at the deep hole.

"Is the whole meteorite in the southern wall?" Deng Weiwei asked.

"At the moment of impact, there was an explosion of dark matter energy, and 80% of the original meteorite evaporated and disappeared in this explosion, the other 5% were exfoliated by the atmosphere when it passed through the atmosphere, and the remaining 5% were scattered around this crater, so the meteorite buried deep in the southern mountain wall today is only one-tenth of the alien visitor." Wu Zhongda replied.

"Then why is it called fire? Could it be that the person who came up with the theory was called Agni, and the crater was named after him? Deng Weiwei asked with a grin.

"The real reason is that this meteorite assay came from a planet called Agni." Wu Zhongda also laughed.

"Professor Wu, would you like to share your thoughts on this crater?" Deng Weiwei asked.

"A seemingly insignificant small celestial body can knock out a crater ten times its own size in the ground, causing complete damage to the local natural environment." Wu Zhongda took the microphone and said, "Although everyone is only seeing this simple crater in front of you, you must always remember that this crater is only caused by a celestial body with a diameter of 100 meters, and there are billions of such meteors and their fragments in the sky above Planet Gliss!" And they are still colliding with each other, and the number is still increasing. ”

Deng Weiwei's face was a little stiff.

"As you may already know, the vicissitudes of life over hundreds of millions of years are a slow process of nature changing into new clothes, but there are times when the relative natural environment changes dramatically. Whenever such a drastic change occurs, not only will the topography change in an instant, but the survival and reproduction of thousands of organisms will also be profoundly affected. (To be continued.) )