At the 2019 Oscar ceremony, the film “First Man” depicting the process of landing on the moon won the best visual award.
This movie tells the exciting past of Apollo 11 when it landed on the moon from Armstrong’s personal perspective.
However, the lack of a detail in the movie also made many Americans, including Trump, speak out against it.
What makes them angry is that the film does not show the stars and stripes on the moon.
Although the director later explained that this was done through artistic sublimation, the dispute still did not subside.
Because in the eyes of some people, such solid evidence as the national flag cannot be ignored.
Just like astronauts’ footprints on the moon, it has profound significance.
Speaking of which, I believe many people will be curious, will the traces left on the moon in the Apollo moon landing program, such as the American flag, the footprints of astronauts, the ruts of space vehicles and some discarded equipment, always be there?
Will the traces of landing on the moon disappear?
Apollo 11 landed on the moon for the first time in 1969. In the following years, Apollo 12 and Apollos 14-17 landed on the moon successively. A total of 6 missions were successfully completed and 12 astronauts set foot on the moon.
Until 1972, no one set foot on the moon after Apollo 17 returned home.
Human beings go to the moon with dreams and then return with full loads. what remains on the moon is a series of “human marks”.
So, can these traces resist time?
From the perspective of physical laws, these traces may not disappear for a long time.
Because the moon is different from the earth, it has no atmosphere, no wind and rain, no scouring by liquid water, no destruction by volcanic activities, etc., so the things that fall on the surface of the moon may remain the same for a long time.
The only threat to these marks may be factors outside the moon, such as meteorite impacts or solar wind erosion.
However, the probability of meteorites destroying lunar landing sites is not very high, and the solar wind is very slow, which is a very long process.
According to the study of moon rocks collected by astronauts during Apollo missions, scientists have learned that rocks are eroded at a rate of about 0.04 inches (1.016 millimeters) every 1 million years.
Therefore, from this perspective, unless someone is covered by the factors, the traces left by astronauts may have been watching alone on the moon for a long time.
Can we know the truth from the picture?
In theory, so, what about the real situation?
For this problem, the best method of proof is to find evidence of “seeing is believing”, such as through spacecraft or field research.
However, in the past few decades, human beings have never set foot on the moon again and have no chance to approach these traces.
In 2009, NASA launched the Lunar Reconnaissance Orbiter (LRO), a probe that orbits the moon and can observe the moon’s surface at close range.
Therefore, in the course of its operation, it took the clearest picture of the moon landing site so far.
By comparing these clear pictures with those taken during the mission, scientists can distinguish the traces of objects left on the moon according to bright objects and their shadows, combined with the relative positions in the original records, including obvious marks.
For example, Mars rovers, thermal blankets and backpacks, flagpoles and flags used on the moon.
But for the nylon star-spangled banner, Arizona State University scientist and LRO camera chief researcher Mark Robinson once judged that they might have been beyond recognition.
Because of extreme temperature changes on the moon and strong ultraviolet radiation, the flag is likely to have faded or even been severely deformed.
Pearlman, an expert in space history and collectibles, also holds the same view: “Under the harsh conditions on the moon’s surface, the materials of the flag will definitely be seriously damaged.”
In the pictures released by LRO, ruts and tracks left by people can be seen, although NASA marked the objects in the pictures according to scientific analysis.
However, for more detailed places, such as the present appearance of the star-spangled banner and the disappearance of those precious footprints, it may still need to wait for further confirmation from other lunar exploration missions. After all, the details of the photos taken so far are not convincing enough.
But will these marks last forever? This problem does not need to be verified.
Because although the natural erosion of the moon’s surface is very slow, it will wear out after all. As long as the time is long enough, these traces will disappear naturally (according to the estimation of footprint 1cm thick, it will take 9.84 million years to completely disappear).
In front of a long time, nothing will be eternal.
So is the earth, so is the moon.