Science and Technology Daily reporter Tang Fang
Recently, the Arizona State University Lunar Reconnaissance Orbiter Camera (LROC) project team announced that by analyzing lunar images, they confirmed that two large craters were knocked out of the lunar surface. The impact location is Hertzsprung crater on the far side of the moon.
Figure 1: LROC high score ratio image. The arrows point to two new impact craters formed by the impact event on March 4, 2022. Picture source: NASA/GSFC/Arizona State University
On March 4 this year, a flying object weighing about 3 tons crashed into the back of the moon. "The astronomical community generally believes that the flying object is a rocket wreckage, but no one has claimed it. Now it is found that it has 'one impact and two craters'. This is the mystery of it." Huang Shaopeng, a professor at Shenzhen University, told a reporter from Science and Technology Daily on the 27th.
hit a double crater with a maximum width of 29 meters.
The LROC project team compared the high-resolution images of February 28 and May 21 and found that: The two craters have diameters of 16 meters and 18 meters respectively, and they partially overlap. It is a chain pit.
What kind of "extraterrestrial visitor" caused such an impact crater?
Huang Shaopeng said that the astronomical community generally believes that the flying object is a rocket wreckage. He introduced that the wreckage of the deep space exploration launch vehicle falling on the moon had happened many times as early as the Apollo era. Since humans began to explore space, the third stage of the Saturn 5 rocket carrying the American Apollo 13, 14, 15 and 17 has all crashed onto the lunar surface.
Figure 2. The impact crater formed by the wreckage of the Apollo launch vehicle falling on the lunar surface. Picture source: NASA/GSFC/Arizona State University
But what is puzzling is that there is usually only one impact crater when the rocket body debris falls, and the Apollo launch vehicle debris also forms a single impact crater. Huang Shaopeng explained that this is because one end of the rocket body is the engine and the other end is the fuel tank. After the fuel is exhausted, it will be empty, and only the engine end is heavy.
In Huang Shaopeng's view, the aircraft hit two craters on the moon, indicating that it is likely to be a "two-headed" guy.
It has been 7 years since the flying object was first discovered.
As early as March 14, 2015, the flying object was first discovered by the Catalina Sky Survey of the United States. At first, the discoverers believed that the flying object was a near-Earth asteroid , and assigned it the number WE0913A. However, a Brazilian astronomer analyzed the flight trajectory of this object and found that the object was orbiting the earth instead of the sun. Therefore, he judged that it may not be a natural asteroid but a man-made space junk.
Huang Shaopeng said that the flying object numbered WE0913A was discovered in Earth orbit , so it was deemed to be man-made. But its orbit is different from most artificial satellites or space junk in that it is very high and far away from the earth, so it was mistaken for an asteroid at first.
"When it was first discovered, the flying object was orbiting the earth like the moon, each going its own way. But because its orbit is far away from the earth, it may move closer to the moon. Once it enters Within the scope of the moon's influence, it may be captured by the moon and eventually enter the path of falling." Huang Shaopeng gave his analysis.
"From the discovery of the flying object in 2015 to the impact in 2022, this serendipitous process took more than seven years." Huang Shaopeng said.
The identity of the flying object remains a mystery
In January this year, American astronomer Bill Gray predicted that the flying object numbered WE0913A would hit the back of the moon on March 4, 2022.
As the predicted fall time approaches, this topic becomes hotter. Gray had speculated that the flying object was the remains of the Falcon 9 launch vehicle.Because on February 11, 2015, the American commercial aerospace company SpaceX used a Falcon 9 launch vehicle to launch the deep space environmental observation satellite DSCOVER for the National Oceanic and Atmospheric Administration (NOAA). Gray also used relevant computing software to predict that this flying object floating in the high orbit of the Earth would be captured by the moon and hit the moon.
But NASA experts pointed out after checking the relevant orbit data that DSCOVER is too far away from the moon, and its launch vehicle debris cannot fall into the orbit captured by the moon.
Regarding this discovery, the LROC project team stated that the origin of the aircraft is still uncertain, but the feature of serial pits may help confirm its identity in the future.
Editor: Liu Yiyang
Review: Yue Liang
