As many have already noticed, the Moon is always turned to the Earth by the same side. The question arises: is the rotation of these celestial bodies around their axes synchronous relative to each other?
Although the Moon rotates around its axis, it always faces the Earth with the same side, that is, the Moon's rotation around the Earth and rotation around its own axis is synchronized. This synchronization is caused by the friction of the tides that the Earth produced in the lunar shell.
Another mystery: does the moon rotate on its axis at all? The answer to this question lies in resolving the semantic problem: who is at the forefront - an observer on Earth (in this case, the Moon does not rotate around its axis), or an observer in extraterrestrial space (then the only satellite of our planet rotates around its axis).
Let's do this simple experiment: draw two circles of the same radius, touching each other. Now imagine them as discs and mentally roll one disc along the edge of the other. In this case, the rims of the discs must be in continuous contact. So, how many times do you think the rolling disk will turn around its axis, making a full revolution around the static disk. Most will say once. To test this assumption, take two coins of the same size and repeat the experiment in practice. And what is the result? The rolling coin has time to turn around its axis twice before it makes one revolution around the stationary coin! Are you surprised?
On the other hand, does the rolling coin rotate? The answer to this question, as in the case of the Earth and the Moon, depends on the observer's frame of reference. The moving coin makes one revolution relative to the starting point of contact with the static coin. In relation to an outside observer, in one revolution around a stationary coin, a rolling coin turns twice.
Following the publication of this coin problem in Scientific American in 1867, the editorial board was literally inundated with letters from indignant readers who held the opposite opinion. They almost immediately drew a parallel between the paradoxes with coins and celestial bodies (the Earth and the Moon). Those who adhered to the point of view that a moving coin in one revolution around an immovable coin once manages to turn around its own axis, were inclined to think about the inability of the moon to rotate around its axis. Readers' activity regarding this problem has increased so much that in April 1868 it was announced that the controversy on this topic was stopped in the pages of Scientific American. It was decided to continue the controversy in the magazine The Wheel, specially devoted to this "great" problem. One number,at least got out. In addition to illustrations, it contained a variety of drawings and diagrams of intricate devices created by readers in order to convince editors that they were wrong.
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Various effects generated by the rotation of celestial bodies can be detected using devices like Foucault's pendulum. If it is placed on the Moon, it turns out that the Moon, revolving around the Earth, makes revolutions around its own axis.
Could these physical considerations act as an argument confirming the rotation of the moon around its axis, regardless of the observer's frame of reference? Oddly enough, from the point of view of general relativity, probably not. In general, we can assume that the Moon does not rotate at all, it is the Universe that revolves around it, while creating gravitational fields like the Moon revolving in motionless space. Of course, it is more convenient to take the Universe as a stationary frame of reference. However, if you think objectively, with regards to the theory of relativity, the question of whether this or that object really rotates or is at rest is generally meaningless. Only relative motion can be "real".
To illustrate, imagine that the Earth and the Moon are connected by a barbell. The rod is fixed on both sides rigidly in one place. This is a situation of mutual synchronization - one side of the Moon is visible from the Earth, and one side of the Earth is visible from the Moon. But this is not how Pluto and Charon rotate. And we have a situation - one end is rigidly fixed on the Moon, and the other moves along the surface of the Earth. Thus, one side of the Moon is visible from the Earth, and different sides of the Earth from the Moon.
Instead of a barbell, gravity acts. And its "rigid attachment" causes tidal phenomena in the body, which gradually either slow down or accelerate the rotation (depending on whether the satellite rotates too quickly or too slowly).
Some other bodies in the solar system are already in this synchronization too.
Thanks to photography, we can still see more than half of the moon's surface, not 50% - one side, but 59%. There is a phenomenon of libration - the apparent oscillatory motion of the moon. They are caused by irregularities in orbits (not ideal circles), tilts of the axis of rotation, and tidal forces.
The moon is in tidal grip on the Earth. Tidal capture is a situation when the period of revolution of the satellite (Moon) around its axis coincides with the period of its revolution around the central body (Earth). In this case, the satellite always faces the central body with the same side, since it revolves around its axis for the same time it takes to orbit around its partner. Tidal capture occurs in the process of mutual motion and is characteristic of many large natural satellites of the planets of the solar system, and is also used to stabilize some artificial satellites. When observing a synchronous satellite from the central body, only one side of the satellite is always visible. When viewed from this side of the satellite, the central body "hangs" motionless in the sky. From the back side of the satellite, the central body is never visible.
Moon facts
There are moon trees on earth
Hundreds of tree seeds were brought to the moon during the 1971 Apollo 14 mission. Former American Forestry Officer (USFS) Stuart Roose took the seeds as personal cargo as part of the NASA / USFS project.
Upon their return to Earth, the seeds germinated, and the resulting moon seedlings were planted throughout the United States as part of the country's bicentennial celebration in 1977.
There is no dark side
Place your fist on the table, fingers down. You can see the back of it. Someone on the other side of the table will see knuckles. This is how we see the moon. Since it is tidally blocked in relation to our planet, we will always see it from the same point of view.
The notion of the "dark side" of the moon came out of popular culture - remember Pink Floyd's 1973 album "Dark Side of the Moon" and the thriller of the same name in 1990 - and actually means the far, night side. The one that we never see and which is opposite to the side closest to us.
Over a period of time, we see more than half of the moon, thanks to libration
The moon moves along its orbital path and moves away from the Earth (at a rate of about one inch per year), accompanying our planet around the sun.
If you looked up at the Moon as it accelerated and decelerated on this journey, you would also see it wobble from north to south and from west to east in a movement known as libration. As a result of this movement, we see a part of the sphere, which is usually hidden (about nine percent).
However, we will never see another 41%.
Helium-3 from the Moon could solve Earth's energy problems
The solar wind is electrically charged and from time to time collides with the Moon and is absorbed by the rocks of the lunar surface. One of the most valuable gases in this wind that is absorbed by the rocks is helium-3, a rare isotope of helium-4 (commonly used for balloons).
Helium-3 is perfect for meeting the needs of nuclear fusion reactors with subsequent power generation.
One hundred tons of helium-3 could meet the energy needs of the Earth for a year, according to calculations by Extreme Tech. The lunar surface contains about five million tons of helium-3, while the Earth has only 15 tons.
The idea is this: we fly to the moon, extract helium-3 in the mine, collect it in tanks and send it to Earth. True, this may not happen very soon.
Is there some truth in the myths about full moon madness?
Not really. The assumption that the brain, one of the most watery organs of the human body, is influenced by the moon, is rooted in legends that are several millennia old, even in the time of Aristotle.
Since the gravitational pull of the moon controls the tides of the earth's oceans, and humans are 60% water (and 73% brain), Aristotle and the Roman scientist Pliny the Elder believed that the moon should have a similar effect on ourselves.
This idea gave rise to the terms "lunar madness", "transylvanian effect" (which became widespread in Europe during the Middle Ages) and "lunar madness". Films of the 20th century added fuel to the fire, linking the full moon to psychiatric disorders, car accidents, murders and other incidents.
In 2007, the government of the British seaside town of Brighton ordered additional police patrols to be sent during full moons (and on payday too).
Yet science says there is no statistical relationship between human behavior and a full moon, according to several studies, one of which was conducted by American psychologists John Rotton and Ivan Kelly. It is unlikely that the moon affects our psyche, rather it simply adds light, in which it is convenient to commit crimes.
Lost moonstones
In the 70s, the Richard Nixon administration distributed stones brought from the lunar surface during the Apollo 11 and Apollo 17 missions to leaders of 270 countries.
“We would like to share these stones with all the countries of our world,” said Apollo 17 astronaut Eugene Cernan.
Unfortunately, more than a hundred of these stones have gone missing and are believed to have gone to the black market. While working for NASA in 1998, Joseph Gutheinz even conducted a covert operation called "Lunar Eclipse" to end the illegal sale of these stones.
What was all this hype about? A pea-sized slice of moonstone was valued at $ 5 million on the black market.
The moon belongs to Dennis Hope
At least he thinks so.
In 1980, exploiting a loophole in the 1967 UN Space Property Treaty that "no country" could claim the solar system, Nevada resident Dennis Hope wrote to the UN and announced the right to private property. He was not answered.
But why wait? Hope opened a lunar embassy and began selling one-acre plots for $ 19.99 each. For the UN, the solar system is almost the same as the world's oceans: outside the economic zone and owned by every inhabitant of the Earth. Hope claimed to have sold extraterrestrial real estate to celebrities and three former US presidents.
It is unclear whether Dennis Hope really does not understand the wording of the treaty or is trying to force the legislature to make a legal assessment of its actions so that the development of heavenly resources can begin under more transparent legal conditions.
