Sun Tan still distrusts Nina. After all, the two of them had just met, and there was no problem with their actions this time. In this situation, if they were caught, they would die. However, Mark still agreed to her request. Although the two did not know each other very well, Mark felt that she was a sincere person from the brief contact, and what she said did touched him. The more important issue was human resources. Although confidentiality is important, it was difficult for them to do anything. It was always good to have one more person to help.

So at Mark's insistence, Sun Tan still brought her with her. The military armored cockpit was used for two people, but they were all thinner and could barely sit down. After Sun Tan activated his horsepower and escaped the pit, Mark saw an amazing scene on the ground.

The earth is covered with complex black networks, like blood vessels rising on the skin. The white ground is torn apart, which makes people feel broken at first glance. Those grounds that are cracked in the earthquake, stretching for dozens of kilometers, are extremely spectacular. No one knows the cause of the earthquake, which may be related to the impact of the mysterious Cube, but there is no doubt that this will not be the last disaster, and more unexpected disasters will follow after this.

A group of people drove military multi-functional self-propelled armor through the above ground sink. The mecha was equipped with an ion propeller and flew by jetting ion plasma. Its endurance was not strong, but at least it could allow them to leave this area. Sun Tan was not very good at driving. If it weren't for the mecha's sem and assisted driving, he would definitely drive into the ditch. After Mark came up, he gave up his driving position to Mark.

"Okay, let's talk about your plans now." Mark asked Sun Tan while familiarizing himself with the operating table.

"Then I said that, in fact, I was at a loss a few days ago. I had been thinking about how to simulate and enhance our transmission signals, but there was no breakthrough. In depressed, I went to read my grandfather's works, hoping to find some inspiration. I have to say that although the old man was very smart, he didn't like to speak human words and few people could understand what he wrote." Sun Tan said as he took out a worn paper book from his bag, with a few big words printed on the faded cover - Moon Conjecture.

"I didn't expect you to have something older than that machine." Mark complained that paper books can really be used in museums until now. There were no paper books on Earth at the end of the 21st century, let alone on the moon without trees at all.

"Is it rare? I have more ancient fun things." Nina blinked.

"In short, he wrote some of his research and hypotheses about the moon. He collected and analyzed some of the moon's rocks and found that the density of the rocks collected from different places and states was surprisingly high. If there is a liquid core inside the moon or a solid rock composed of solid rocks, the mass should be several times larger than now!" Sun Tan took out a pile of ancient paper pieces from the mezzanine of the book, some of which were clippings and some were photocopied paper fragments. "However, the moon does not have the high quality that matches it. It has been hanging on our heads for thousands of years, so we are used to it and never thought it was abnormal. Its mass is too light. If it is a normal satellite, the deflection angle of the earth will be larger, the four seasons will be longer, and the tide activity will be more intense, but none of these are there anything hidden inside the moon. This is a hollow planet!"

"What?" Mark has lived on the moon for so many years and has heard such a statement.

"It is indeed possible." Nina added: "When I was doing geological research, I also discovered this strange phenomenon. When a solid object is hit, two types of waves can be detected, one is longitudinal wave and the other is surface wave, while hollow objects can only measure surface waves. Longitudinal waves are a kind of penetration wave that can penetrate objects, and surface waves can only be transmitted on extremely shallow surfaces. I have worked on the lunar geological base for a period of time. After a long period of recording, no longitudinal waves were recorded, and all of them were surface waves."

"Then what, what does that mean?" Mark felt deeply that he was a little uninformed and had no idea what method he could come up with to save the earth through this conclusion.

"The next thing is the key point. Now the exploration of the moon is very in-depth. Scientists once used satellite technology to scan the entire moon surface and draw a complete map of the moon's magnetic field, but there are still many areas that are undetected. Those places seem to be blocked by some signal. My grandfather recorded a news. An astronaut detected a metal signal underground in the signal-free area. He suspected that there were huge metal veins underground, but it was quickly denied. The signal was like a ghost and sometimes disappeared, and in the end it could only be left alone." Sun Tan said this and suddenly became excited. He raised a finger and said, "That may be the trace left by other civilizations. Although we don't know what it is, we must go and see. If we can find spaceships or base stations of alien civilizations, maybe we can use their technology."

"Use their technology to send messages to the hijackers. If the aliens on the moon are advanced civilizations, they can shock the other party!" Mark finally realized the key point.

"So that's it, you're so smart!" Nina suddenly realized after hearing their plan.

"But it is still a bit difficult to implement. I recorded all the unknown points at present." Sun Tan took out a tablet from his bag and opened a map software. It was a dense list of places where he had marked them. If they went to search one by one, they would probably not be able to find them in a few months, let alone they didn't have several months. The fuel and supplies on this mecha were limited, so they could only go to less than ten locations at most.

"Damn, why are there so many places where these are hidden spaceships?" Mark looked shocked with a flat plate.

"No, some of them are the places we are looking for, most of them are caused by the lunar magnetic field itself," said Sun Tan.

"Then there is no way to bet! Go to the nearest one!" Mark slapped the steering wheel and shouted.

"Go here." Just as they were about to take a gamble, Nina stretched out a slender jade finger and clicked on the map. Her crisp and moving voice was like a rain, giving Mark a timely revelation, "Do you remember the legend I told you? My ancestors drew a complete moon map hundreds of years ago, and even many unknown places today, they have records. The Great Prophet once said the place he dreamed of, the place where the rivers gushed out of the moon, here."

"It's so charlatan, I won't believe it." Sun Tan said with a disdainful look on his face.

"It's always better than Mon, let's go!" Mark turned around and added accelerator, and drove towards the place where Nina said.
Chapter completed!