On March 5, according to foreign media reports, at 7:25 a.m. Eastern time on Friday, a fragment of a rocket that had been flying in space for seven years and weighed about 4 tons hit the back of the moon. The impact is unclear, and the crater may not be observed until weeks or even months later p> < p > < / P > < p > scientists speculate that the rocket fragment hit the hertzspringer crater on the back of the moon at a speed of 9288 kilometers per hour. The energy generated by the collision will form an impact crater, which may be 66 feet (20 meters) in diameter. In addition, the impact is likely to blow the lunar dust to an altitude of hundreds of kilometers p> < p > this rocket fragment was discovered by the Catalina Sky Survey Telescope in the United States and was later named we0913a. However, we0913a does not orbit around the sun like an asteroid, but around the earth. Therefore, the American astronomer bill gray suspected that it was an artificial object and predicted for the first time that it would collide with the moon in March 2015 p> < p > according to scientists, this is the first time that space debris has accidentally hit the surface of the moon. Because it hit the back of the moon, scientists cannot observe the impact for a period of time. The final impact can not be observed until the satellites orbiting the moon move to a suitable orbit, such as NASA's lunar survey orbiter and India's lunar ship 2 spacecraft p> < p > it may take scientists months to find the crater, but scientists hope these images will help them better understand the situation below the surface of the moon. And what impact will it have on the lunar surface when it is hit by an object with known speed and mass p> < p > considering the speed of rocket debris flying, it is likely that it will not leave any evidence of existence except for the impact crater. At the moment the rocket hits the moon, the shock wave will pass through the whole debris in just a few milliseconds and smash it into metal fragments p> < p > although this is the first piece of space junk to accidentally collide with the moon, it is not the first time that a man-made object crashed on the moon. In 2009, NASA's Lunar Crater Observation and sensing satellite deliberately hit the south pole of the moon at a speed of 9000 kilometers per hour, releasing plumes that enable scientists to detect the chemical characteristics of water ice. NASA also sent the Apollo Saturn V rocket to the moon. (small) < / P > < p > related reading: < / P > < p > < / P > < p > China has denied, and it is not the United States! Whose is the mysterious spacecraft that hit the moon on March 4 p> < p > source: & nbsp; Flower growers on the road to the stars & nbsp& nbsp; p> < p > < / P > < p > on January 21, 2022, American astronomer bill gray published a rather surprising information on the "projectpluto" website that a mysterious object weighing 4 tons will hit the hertzsprung crater on the back of the moon at a speed of 2.58 km / s p> < p > the impact energy of this object is equivalent to 3.2 tons of TNT explosion equivalent, which will leave an artificial crater with a diameter of 20 meters on the moon. However, several origins of this mysterious object have been expelled and denied one by one. Where it comes from has become a mystery p> < p > the orbit of this object is similar to that of SpaceX rocket. It is also similar to the chang'e-5 t mission < / P > < p > bill gray first tracked this object on January 1. Originally, this is a tracking of conventional space debris. This is an object with a perigee near the earth but an apogee near the lunar orbit. It is difficult to confirm how long it has been in this orbit, But Bill found that a close encounter with the moon on January 5 would significantly change its orbit p> < p > after calculating the new orbit of the celestial body, Bill found that it will directly hit the moon for the third time after completing two orbits around the earth. The time points to 12:25:58 on March 4. The impact position is located at + 5.18 ° latitude and 233.55 ° east longitude of the moon. More accurate coordinates can only be confirmed after continuously tracking the orbit p> < p > the impact point is near the hertzsprung crater in the northern hemisphere on the back of the moon. The diameter of the crater is 520km. The exact impact point is located at the edge of the crater, which will leave a permanent mark. Unfortunately, because the moon is locked by the earth tide, the back cannot be seen on the earth, so it is estimated that this impact can only be observed by the LRO around the moon, It also depends on its detour position. Of course, the vibration generated by the impact will be detected by the lunar earthquake detector of Chang'e 4 p> < p > which country launched this object p> < p > bill thought that the celestial body should be 2015-007b when it was released on January 21. This is the second stage rocket launched by SpaceX's falcon-9 rocket in 2015. Dscovr is the space climate observation satellite of the U.S. Oceanic and Atmospheric Administration (NOAA), which is located in the heliocentric orbit at L1 of the Lagrange point p> < p > dscovr < / P > < p > therefore, the falcon-9 two-stage rocket will cross the moon when it is launched, so the orbit of the two-stage rocket is basically enough to reach the lunar orbit. After that, the satellite will continue to fly to point L1 with its own power until it is accurately positioned. Because the speed of the two-stage rocket has reached the speed of the lunar earth transfer orbit, Therefore, it is likely to stay in this orbit for a long time p> < p > launch trajectory: blue is the earth, yellow is the moon, and purple is the probe < / P > < p > on February 12, Bill gray corrected his judgment after obtaining JPL (NASA's Jet Propulsion Laboratory) data. He originally thought that the launch mission of falcon-9 in 2015 was denied, Closer to this target orbit should be the chang'e-5 T1 spacecraft mission launched by China on October 13, 2014 p> < p > this T1 aircraft is a mission for the field test of Chang'e 5's return orbit. Its orbit is to return directly after flying around the moon, enter the earth's atmosphere directly at the speed of the second universe in the form of water drift trajectory, and land after two jumps and deceleration. The rocket launching T1 aircraft is the Long March 3 C-2, When it separated from the T1 rocket, the three-stage rocket had sent it into the Earth Moon transfer orbit. Theoretically, the three-stage rocket could indeed land in the lunar orbit p> < p > the length of the three-stage rocket from Long March III C to II is 12.375 meters and the diameter is 3 meters. The fuel used is liquid hydrogen and liquid oxygen. The volume is indeed relatively large, but the empty weight is not large p> < p > however, on February 21, the Chinese Ministry of Foreign Affairs issued a statement saying that 2015-007b was not a three-stage rocket to launch the chang'e-5 T1 aircraft. The rocket had re entered the earth's atmosphere a week after the launch mission and had fallen into the Pacific region p> < p > why is it so difficult to track an object? It may be an alienHuman aircraft p> < p > since 2014, the number of man-made celestial bodies launched to the moon or beyond the moon's orbit has not been large. According to the orbit of this celestial body, we can deduce its original orbit to find out which launch it is? There is really no problem in theory, but it is difficult to track in practice, because it faces the following problems: < / P > < p > 1. Accurate orbit tracking requires time and energy. In fact, the difficulties are the smallest p> < p > 2. Orbit change of celestial bodies, external causes: orbit change caused by the influence of light radiation dynamics and lunar gravity p> < p > 3. Orbital changes of celestial bodies, internal causes: orbital changes caused by internal fuel leakage p> < p > as time goes on, it becomes more and more difficult to restore its original orbit, because there are more and more orbit accumulation errors, so it will be even more unable to track which original object is. Now bill gray has encountered this problem. However, according to the spectral analysis on February 16, he thought it was the T1 aircraft of Chang'e V, but the Chinese Ministry of Foreign Affairs issued a statement on February 21, Said that after a detailed investigation, this is the official conclusion p> < p > whose is this celestial body p> < p > I have been unable to confirm the information of this celestial body. If I have friends, I will open my mind. There was a black knight satellite in those days. Can't there be a "White Knight" satellite now? Maybe aliens sent into the solar system to monitor the earth in earth orbit. Now the task is completed, and they are about to crash into the moon and destroy the corpse p> < p > in fact, to be exact, the Black Knight satellite does not exist. Many descriptions of the satellite are contradictory. For example, on December 18, 2021, online media space published an article saying that the "Black Knight" satellite had been shot down four years ago, with pictures attached p> < p > the video said that the red circle was the fighter plane of the Illuminati < / P > < p > on March 20, 2017, the oil pipe published a title entitled "led clip of alien satellite being shot down? 3 / 19 / 17", It was the Illuminati fighter that shot down the Black Knight, and when the "Black Knight" satellite was hit, an escape pod was separated from the satellite, and finally disappeared into the night sky with unknown whereabouts p> < p > the video calls it a separate escape pod < / P > < p > but there are too many mistakes in this video. First, it is possible for a fighter to shoot down a satellite, but the fighter cannot fly out of the atmosphere and can only use missiles. There are many problems here. The easiest way to shoot down a satellite is an anti satellite missile on the ground, which does not need a fighter. The other is that the satellite orbit is very high, Fighter planes need to launch missiles from a long distance. Even if they shoot down satellites, they can't be photographed at the same time p> < p > the other is that the satellite shot down in space is only one flash at most, and there will be no long wake, because the satellite has no atmosphere at its height, and even if it is destroyed, it will not flash like a meteor p> < p > the absence of the Black Knight certainly does not mean that the "White Knight" does not exist, but this brain hole is too big. There is no need to prove such a conjecture, but there is no chance to prove it. It will fall into the moon on March 4. It's too late to go and have a look. (end) < / P > < p > < / P > < p >