The hidden but wonderful side of the moon

Abstract

The mysterious glow of the moon has always been the subject of people's imaginations and the subject of countless legends around the world, especially since man first set foot on the moon, the attraction of this celestial neighbor has increased even more. However, while the visible part of the moon has been widely studied and explored, the far part of the moon is still elusive in mystery. In this article, I will look at the hidden half of the moon and explore the new findings surrounding it.

Introduction

The far side of the moon is a hemisphere of the moon that cannot be seen from the Earth due to the simultaneous positional and translational motion. But its surface is full of rough surfaces compared to the near-Earth side, and with many impact craters and little flat plains, it appears to be similar to other barren places in the solar system, such as Mercury and Callisto. This hemisphere is sometimes Also called the "dark side of the moon", where "dark" doesn't mean not receiving sunlight, but "unknown" -, both sides of the moon experience two weeks of sunlight, and one side isn't visible from Earth because when the back of the moon is facing the sun, it is located in the space between the earth and the sun, and the side facing the Earth is dark (new moon).

The reason for this is that the period of the moon's rotation corresponds to its orbital period, which means that for every orbit it makes, it goes around itself once: in simpler terms, it can be said that the moon has a duration of a day and a year. equal to each other. (~29.5 Earth days).

It should be noted that 18% of the far side of the Moon is sometimes visible from Earth due to the Moon's motion fluctuations. However, the remaining 82 percent was not seen until 1959 when it was photographed by the Soviet Luna 3 space probe. The Soviet Academy of Sciences published the first lunar atlas in 1960. Apollo 8 astronauts were the first humans to orbit the moon in 1968. In fact, until January 3, 2019, when the Chang'e-4 spacecraft made its first landing on the far side of the Moon, all manned and unmanned soft landings on the visible side of the Moon had been completed.

Early Exploration

Before space exploration, astronomers did not expect the far side of the moon to be different from the visible side. But gradually this idea disappeared. On October 7, 1959, the Soviet Luna 3 probe took the first photographs of the far side of the Moon, eighteen of which were acceptable, covering one-third of the Moon's invisible surface. The images were analyzed and the first atlas of the far side of the Moon was published by the USSR Academy of Sciences on November 6, 1960. It contained a catalog of 500 prominent moon complications.

In 1961, the first sphere (scale 1:13600000) containing semi-invisible features of the Moon was released in the Soviet Union based on Luna 3 images. On July 20, 1965, another Soviet probe, Zond 3, sent back 25 very good quality pictures of the far side of the Moon, with much better resolution than Luna 3. In particular, the images showed a chain of craters hundreds of kilometers long, but surprisingly no flat plains like those seen from Earth with the naked eye were visible from the visible surface of the Moon.

In 1967, the second part of the Lunar Half Atlas was published in Moscow, based on data from Zond 3, and included 40 newly discovered features of the moon's distant landscape. The same year, the first full moon map (scale of 1:5000000) and the updated full sphere (scale of 1:100,000,000), comprising 95% of the Moon's surface, were released in the Soviet Union.

Since many prominent features of the far side of the moon were discovered by Soviet space probes, Soviet scientists named them. This caused controversy. Although the International Astronomical Union (IAU) left many of these names intact, but later assumed the role of naming the lunar features in the hemisphere.

Missions for further investigation

On April 26? 1962? NASA's Ranger 4 space probe became the first spacecraft to orbit the moon? but it collided with the lunar surface during landing? and failed to send any scientific data even before it hit the moon.

The first truly comprehensive and detailed survey of the far side of the Moon was conducted by NASA's American Unmanned Orbiter Program from 1966 to 1967. However? much of the moon's far-side coverage was later carried out by the Lunar Orbiter 5 probe.

The far side of the moon was first seen directly by the human eye during the Apollo 8 mission in December 1968. Twenty-four people from Apollo 8 and 10 to Apollo 17 have seen the other side of the moon.

Hidden Secrets

The hidden half of the moon has attracted the attention of astronomers because of its dramatic differences with the visible part. One of the most striking differences is the lack of dark great plains and instead the dominance of rugged and mountainous terrain in the hidden part of the moon. The two hemispheres of the moon have completely different appearances, the side facing the Earth is covered by numerous flat plains, the far side is full of puddles, and the areas full of craters.?This has led to speculation that the back of the moon may have experienced more meteorites compared to the front.

?According to observations and surveying, only 1% of the surface of the far side of the moon is covered by the plain, which is a significant difference compared to 31.2% on the nearby side.?An accepted explanation for this difference relates to the higher concentration of heat-producing elements in the nearby hemisphere, the difference is well illustrated by geochemical maps obtained from the Lunar Prospector gamma-ray spectrometer. Other reasons for this difference include the height of surface features and thickness of the basaltic crust, although these reasons do not explain why the Antarctic Basin (which includes the lowest elevations of the Moon and has a thin crust) is not as active as Oceanus Procellarum near the Moon.

Some researchers believe that differences between the two hemispheres may have been caused by a smaller sphere hitting the Moon in the past, or even the effects of a pre-moon (Theia) collision with Earth. Because only a massive global impact can cause a massive heat wave across the entire surface of the moon, separating the material of the shell and the layers below with such mass differences and reducing the thickness of the shell in the visible part of the moon, but the chemical composition of the far side of the moon contradicts this theory.

In the past, the visible side of the moon was thought to have significant craters, but later due to the effects of the moon's lava flow, the craters have either completely covered or faded, some of which are vaguely visible. The theory that Earth as a protector reduced the number of meteor impacts on the visible surface of the moon is no longer accepted. According to the latest estimates, the Earth is only about 4 the square degree of 41,000 square degrees of sky covers the moon, making the Earth too insignificant as a shield to protect the moon, so both sides may have received an equal number of impacts, but the reappearance of lava has led to the fading of craters near the moon.?

Another theory states that the number of impact craters on the two sides of the moon is due to the Earth's heat at the time of the moon's formation. This is because the lunar crust on the nearby side is mainly composed of plagioclase, which is formed when condensation of aluminum and calcium in combination with the silicate of the mantle of the moon. Meteorite impacts on the nearby side sometimes penetrate the thinner crust. the lava is found to be a very important part of the moon. It removes the basalt that produces the emergence of the plain, but rarely has it happened on the far side.

There is also another difference in the moon's gravitational anomalies. The back of the moon experiences fluctuations in gravitational pull that cannot be explained by the presence of mass alone. Some scientists believe that these anomalies are due to underground lava flows or the thickness difference in the moon’s crust in its halves.

Natural problems

Despite the attraction of the far side of the moon, there are also natural problems that make it challenging to explore and study that part. One of the main obstacles is the impossibility of direct communication.? Because the moon is hidden from Earth, it is difficult to establish a direct line of communication from Earth with foggers or other exploration vehicles. This means that any data collected must first be transferred to a relay satellite or orbiter to be sent to Earth. The complexity of this action adds to the delay caused by the distance from the moon to the Earth to send data, making it difficult to send necessary commands, especially during online observations and tests.

A spacecraft that passes behind the Moon is out of direct radio communication with Earth and must wait in orbit to allow transmission. During one of the Apollo missions, the main engine of the flight module, when the spacecraft was behind the moon, lit up, creating tense moments in the control room before the spacecraft resurfaced.

As a geologist astronaut and the last person to walk on the moon, Harrison Schmidt worked hard to make the Apollo 17 landing on the far side of the moon and envisaged the lava-filled Tsiolkovsky crater. His ambitious proposal included a special communications satellite based on TIROS satellites that would be launched into Farquhar-Lissajous orbit around L2 point to make permanent contact. However, NASA administrators rejected the plans because of the high risk and lack of funding.

Another problem is the lack of sunlight, which makes it harder to use exploration equipment. To overcome this obstacle, scientists have come up with innovative solutions such as equipping the fog with solar panels that can store energy during the moon's day and use it during long nights, or alternative energy sources such as nuclear power to overcome this challenge.

Fortunately? the idea of using Lacrosse Point 2 for communication satellites covering the far side of the Moon has been realized since China’s National Space Administration launched the Queqiao relay satellite in 2018. It has since been used for communications between Lander 4 Change and the Yutu 2 rover? which successfully landed on the far side of the Moon and ground stations in early 2019. It has even been proposed to be considered an ideal location for a fuel depot as part of the warehouse-based space transportation architecture. Astronomers have also proposed installing a large radio telescope on the far side, as it would protect from Earth's radio interference.

Investigating the impact of meteorite impact on the hidden half of the moon

The back of the moon has been exposed to countless meteorite impacts throughout its history. Some of which have been remarkably well preserved. One of the most intriguing aspects of the meteorite impact behind the moon is a phenomenon known as the "mega basin." This massive impact basin, more than 2,500 kilometers in diameter, is believed to have been caused billions of years ago by the impact of a massive asteroid or comet. Examining this crater could provide important information about the early stages of the moon's formation.

The importance of studying the hidden half of the moon for future space exploration

The study of the invisible part of the moon is not only due to the satisfaction of astronomers’ curiosity. Rather, it has practical implications for future space exploration. As a higher station for human missions to other worlds, such as Mars, the Moon plays a role and can provide valuable information about the challenges astronauts may face on long-duration missions and help us develop technologies to overcome them.

In addition, the hidden half of the moon as a pristine environment provides a great opportunity to study the universe beyond our planet. Astronomers can observe galaxies, stars, and other cosmic phenomena with unprecedented clarity, as well as an ideal place to build observatories and radio telescopes. On the other hand, scientists can identify landing sites suitable for future missions and explore the possibility of long-term human habitation on other terrestrial worlds.

The Invisible Part of the Moon Matters to Scientific Research

Understanding the back of the moon has far-reaching implications for scientific research. From planetary geology to astrophysics, understanding the Moon's dark side provides a wealth of information about the formation and evolution of the Solar System. In addition, the Moon is a natural laboratory for studying the effects of space weathering and cosmic radiation. Things like testing the amount and duration of durability of natural and artificial materials in space to investigating the potential of extracting underground resources in a sphere different from the Earth are some of the things that are already on the waiting list of researchers.

Advances in exploring the hidden part of the moon

The Yutu-2 rover by China's Change 4 spacecraft made humanity's first soft landing on the far side of the Moon on January 3, 2019. The spacecraft included a lander equipped with a low-frequency radio spectrometer and geological research instruments. This was the beginning of other exploration projects on the lunar surface, such as the Lunar Surface Electromagnetic Survey rover (LuSEE-Night), a mission for a soft landing in early 2026, designed as a robotic observatory on the far side of the moon that aims to measure Electromagnetic waves.

Besides that, other missions are being planned, including NASA's Artemis program, which aims to return astronauts to the moon and establish a permanent human presence. High-resolution imaging and mapping techniques have allowed scientists to obtain detailed topographical maps of the far side of the Moon and now identify sites for future missions.

Exploring the Secrets Behind the Moon

Technology plays an important role in discovering the secrets behind the moon. Remote sensing instruments, lunar rovers and landers, and advanced imaging techniques have revolutionized our ability to study the moon's hidden secrets. For example, with the help of advanced spectroscopic tools, astronomers can remotely analyze the composition of rocks and minerals. Also, these instruments can detect subtle changes in the composition and topography of the moon.

In addition, robotic missions, equipped with advanced instruments, can independently explore the hidden half of the Moon and collect data without direct human intervention. This reduces the risks associated with human missions and allows for more extensive and complete exploration.

Semi-Hidden Moon Locates Potential Opportunities

Since the disturbing waves sent from the Earth do not reach the far side of the Moon, it is a good place to put radio telescopes. Small, bowl-shaped craters provide a natural site for a stationary telescope similar to the one in Arecibo, Puerto Rico. For much larger radio telescopes, the 100 km diameter Daedalus crater near the center of the far side of the Moon, with a 3 km edge to prevent interference from stray waves from orbiting satellites, as well as the Saha crater, are other potential candidates for radio telescopes.

But before deploying radio telescopes on the far side, several problems must be overcome. The first is lunar dust, which can contaminate equipment, vehicles, and spacesuits. Also, the conductive materials used for radio dishes must be carefully protected against the effects of solar flares. Finally, the area around the telescopes must be protected from contamination by other radio sources.

One of the missions being studied by NASA is to send a rover to the moon to sample the Antarctic basin (the site of a massive impact event with a diameter of approximately 2400 km). Analyzing samples from this part can provide researchers with good information about the depths of the moon.

Because the near side of the Moon is partially shielded from the solar wind by Earth, the far side of the Moon is expected to have the highest concentration of helium-3. This isotope is relatively rare on Earth but has good potential for use as fuel in fusion reactors. Proponents of lunar settlement have cited the presence of this substance as a reason for developing a base on the moon.

ChangE-4 is a Chinese lunar exploration mission that successfully conducted the first soft landing on the far side of the Moon (in the southern polar regions of the Moon) on January 3, 2019. Before that, a communications relay satellite, Queicu, first reached an orbit near the Lagrange L2 lunar point in December 2018. The robotic lander and rover were launched on December 7, 2018, and orbited the Moon on December 12, 2018. Robotic lander for the first time on January 3, 2019 It touched the moon's hidden side and was named the first spacecraft to land on the moon‘s hidden side.

This was followed by the ChangE-3 mission. The ChangE-4 spacecraft was originally built as a backup for ChangE-3, but after ChangE-3 became successful in 2013, ChangE-4 was eventually set up and configured to land on the dark surface of the Moon.? The mission is named after ChangE, the goddess of the Moon, in Chinese culture.

The moon exploration and exploration satellite program by China was planned in three stages:

The first phase is to reach lunar orbit, a goal previously accomplished by ChangE-1 in 2007 and ChangE-2 in 2010.

The second phase of close exploration finally landing on the lunar surface and using a rover to move on the lunar surface was carried out by ChangE-3 in 2013 and ChangE-4 in January 2019.

The third phase is to collect lunar soil samples and send them back to Earth, a mission that will be carried out by the future ChangE-5 and ChangE-6. The goal of the program is to make it possible to land an astronaut crew in the 2030s and possibly build a base near the south pole of the moon. ChangE lunar exploration program was carried out for the first time with a combination of private and corporate investment, a move aimed at accelerating aerospace innovation, reducing production costs, and improving military-civilian relations.

Conclusion

The hidden half of the moon holds a treasure trove of undiscovered items. While the lack of accurate knowledge of its surface complications may be challenging, the advancement in technology and space exploration has brought us closer to uncovering the secrets of this mysterious land. By studying the invisible part of the moon, we can gain a complete understanding of the geological history of the moon and the impact of meteorites hitting the globe, which can provide us with valuable experiences in the field of practical discoveries and scientific research before reaching other planets.