Can you see the earth from the far side of the moon? Why is the Moon facing the Earth on one side? The invisible side of the moon

The Moon floats high in the sky, bright, beautiful, with dark spots on a shiny disk. On a full moon, it resembles someone's round, good-natured, slightly mocking face. We always see her like this. And before us, for thousands of years, people looked at the exact same Moon and dark spots were distributed on it in the same way, which make it look like a human face. For thousands of years, people have been observing the changes in her bright face - from the thin sickle of a newborn month to the full radiance of her disk. Meanwhile, the Moon is a ball, the same as other planets, including our Earth, on which we live. But the moon never shows us its other side, we don't see it. Why?

The moon rotates on its axis and at the same time makes its way around the earth, because it is a satellite of the earth.

In twenty-nine and a half days, it makes its revolution around the Earth, and ... it takes the same amount of time to turn around its axis - it makes this revolution so slowly. And that's the whole point. That is why we always see only one side of it.

But how does it happen anyway? To make this clearer to you, let's do a little experiment. Take some small table (if there is no table - a chair or something else that is more convenient for you, what will be at hand). This chair will be an imaginary Earth, and you yourself will be the Moon, which wraps around the Earth. Start moving around the table, staying facing it all the time. At the beginning of your movement, for example, you saw a window in front of you, but then, as you make your circle around the table (that is, the Earth), this window will be behind you, and only at the end of the path you will see it again . This will only confirm that you have turned not only around the table, but also around yourself, your axis.

So is the Moon. It makes a revolution around the Earth and at the same time around its own axis.

But everyone now knows that we still saw the far side of the moon! How did it happen? Do you remember? .. However, no, you don’t remember this: in those years you were still too small! And this happened in 1959, when Soviet scientists launched an automatic station towards the Moon, which flew around our satellite and transmitted images from its other side to us on Earth. And people all over the world saw the far side of the moon for the first time!

And that's not all. A few years later, Soviet scientists again sent an automatic station towards the Moon, and this time again photographs were taken and sent to Earth. Thanks to the images, scientists then compiled the first map of both sides of the lunar surface, and then a new color map of the Moon with lunar seas, mountain ranges, the most important peaks, ring crater mountains, circuses.

While I was writing these pages, one piece of news followed another. Before I had time to tell you about the new color map, an amazing event took place: in February 1966, the world's first automatic station, our Soviet one, landed on the Earth's satellite! She made, as scientists say, a soft landing - this means that she landed on the moon smoothly, without breaking the equipment.

Having gently landed on the moon, the automatic station immediately began to work hard - it sent more and more pictures of the lunar surface, and these pictures were taken on close range. But this is extremely important! The images were large, accurate: scientists simply pounced on these amazing documents, carefully examined them; now they saw what the surface of the moon is like, what is on it, asserted or, on the contrary, changed their points of view about the lunar surface.

"Luna-9" made a soft landing on our satellite - the Moon. And shortly after that, in March 1966, Luna 10 was launched.

She began to fly around the moon, that is, she became her artificial satellite, and Luna-10 devices sent messages to Earth that research scientists need to know our celestial neighbor better.

"Luna-10" made its endless flight around the Moon, so close, familiar, and in the early days, the whole world could hear the melody of the communist anthem "The Internationale" coming from it.

After "Luna-10" there were also "Luna-11", and "Luna-12", and "Luna-14", and "Luna-16" ... Our messengers are constantly soaring into outer space, they are laying the first paths to our heavenly neighbor. And always the most difficult and most important thing is what is done for the first time!

However, the news recent years amazing! American astronauts, spaceship Apollo 11, Neil Armstrong, Edwin Aldrin and Michael Collins were the first to fly to the moon in July 1969, two of them, Neil Armstrong and Edwin Aldrin, set foot on its surface, the third, Michael Collins, was waiting for them, making circles around the moon .

The names of these cosmonauts will go down in history in the same way as the name of our glorious Gagarin, who was the first to go into space and see our planet Earth from the outside.

And a very special place in the study of our celestial neighbor is occupied by the amazing apparatus "Lunokhod-4", delivered to the Moon in November 1970. He worked hard there, doing the work of exploring the lunar surface for a man. This amazing apparatus worked only on a lunar day, when it could charge its batteries from the energy of the sun. And on a moonlit night, he rested, as they affectionately said about him: he slept.

Really, it all looks like a fairy tale.

And it may well happen that during the time this book is being printed, new amazing events will occur and we will have to expand this chapter, although at the beginning we were going to tell only about one thing: why we do not see the far side of the moon.

Why doesn't the moon rotate and we only see one side? June 18th, 2018

As many have already noticed, the Moon is always turned to the Earth by the same side. The question arises: relative to each other, is the rotation around their axes of these celestial bodies synchronous?

Although the Moon rotates around its axis, it always faces the Earth with the same side, that is, the rotation of the Moon around the Earth and rotation around its own axis are synchronized. This synchronization is caused by the friction of the tides that the Earth produced in the shell of the Moon.

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 located on Earth (in this case, the Moon does not rotate around its axis), or an observer located in extraterrestrial space (then the only satellite of our planet rotates around its own axis). axes).

Let's conduct such a simple experiment: draw two circles of the same radius that are in contact with each other. Now imagine them as discs and mentally roll one disc around the edge of the other. In this case, the rims of the discs must be in continuous contact. So, how many times, in your opinion, will a rolling disk turn around its axis, making a complete revolution around a static disk. Most would say once. To test this assumption, let's take two coins of the same size and repeat the experiment in practice. And what is the result? A rolling coin has time to turn twice on its axis before making one revolution around a stationary coin! Surprised?

On the other hand, does a rolling coin rotate? The answer to this question, as in the case of the Earth and the Moon, depends on the frame of reference of the observer. Relative to the initial point of contact with a static coin, the moving coin makes one revolution. Relative to an outside observer, in one revolution around a fixed coin, a rolling coin rotates twice.

Following the publication of this coin problem in Scientific American in 1867, the editors were 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 held the view that a moving coin has time to turn around its own axis in one revolution around a stationary coin were inclined to think about the inability of the Moon to rotate around its own axis. The activity of readers regarding this problem has increased so much that in April 1868 it was announced that the controversy on this topic in the pages of Scientific American had ceased. It was decided to continue the debate in a magazine dedicated specifically to this "great" problem, The Wheel ("Wheel"). At least one issue is out. In addition to illustrations, it contained a variety of drawings and diagrams of intricate devices created by readers in order to convince the editors of their wrong.

Various effects generated by the rotation of celestial bodies can be detected using devices like the Foucault pendulum. If it is placed on the moon, it turns out that the moon, rotating around the earth, makes revolutions around its own axis.

Can 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, but from the point of view general theory relativity, probably not. We can generally assume that the Moon does not rotate at all, it is the Universe that rotates around it, creating gravitational fields like the Moon rotating in a stationary space. Of course, it is more convenient to take the Universe as a fixed 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 rests is generally meaningless. Only relative motion can be "real".
To illustrate, imagine that the Earth and the Moon are connected by a bar. The bar is fixed on both sides rigidly in one place. This is a situation of mutual synchronization - and one side of the Moon is visible from the Earth, and one side of the Earth is visible from the Moon. But we do not, so Pluto and Charon rotate. And we have a situation - one end is fixed rigidly 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 are visible from the Moon.

Instead of a barbell, the force of attraction acts. And its "rigid mount" causes tidal phenomena in the body, which gradually either slow down or speed up the rotation (depending on whether the satellite rotates too fast or too slowly).

Some other bodies in the solar system are also already in such synchronization.

Thanks to photography, we can still see more than half of the surface of the moon, not 50% - one side, but 59%. There is a phenomenon of libration - the apparent oscillatory movements of the Moon. They are caused by irregular orbits (not perfect circles), tilts of the axis of rotation, tidal forces.

The Moon is in tidal lock 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 rotates around its axis in the same time that it takes for it to turn around in orbit around its partner. Tidal capture occurs in the process of mutual motion and is characteristic of many large natural satellites 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 reverse side of the satellite, the central body is never visible.

moon facts

There are lunar trees on Earth

Hundreds of tree seeds were brought to the moon during the 1971 Apollo 14 mission. Former USFS employee Stuart Roose took the seeds as a personal shipment for a NASA/USFS project.

Upon their return to Earth, these seeds were germinated, and the resulting lunar seedlings were planted throughout the United States, as part of the country's bicentennial celebrations in 1977.

There is no dark side

Place your fist on the table, fingers down. You see its back side. Someone on the other side of the table will see the knuckles. This is how we see the moon. Because it is tidally locked to our planet, we will always see it from the same vantage point.
The concept of the "dark side" of the moon has come from popular culture - think of Pink Floyd's 1973 album "Dark Side of the Moon" and the 1990 thriller of the same name - and actually means the far, night side. The one that we never see and which is opposite to the side closest to us.

In the time span, 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 were to look at the Moon up close as it speeds up and slows down during this journey, you would also see it wobble from north to south and west to east in a motion known as libration. As a result of this movement, we see a part of the sphere that is usually hidden (about nine percent).

However, we will never see another 41%.

Helium-3 from the Moon could solve energy problems Earth

The solar wind is electrically charged and occasionally collides with the Moon and is absorbed by the rocks on the lunar surface. One of the most valuable gases in this wind that are 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 fusion reactors with subsequent power generation.

One hundred tons of helium-3 could supply the Earth's energy needs for a year, according to Extreme Tech's calculations. The surface of the moon contains about five million tons of helium-3, while on Earth it is only 15 tons.

The idea is this: we fly to the moon, extract helium-3 in a mine, collect it in tanks and send it to Earth. True, this can happen very soon.

Is there any truth to the full moon madness myths?

Not really. The assumption that the brain, one of the most watery organs human body, is influenced by the moon, is rooted in legends that are several millennia old, as far back as the time of Aristotle.

Since the Moon's gravitational pull controls the tides of Earth's oceans, and since 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". The films of the 20th century added fuel to the fire, linking the full moon with psychiatric disorders, car accidents, murders and other incidents.

In 2007, the government of the British seaside town of Brighton ordered more police patrols to be sent during full moons (and on paydays too).

And yet science says that there is no statistical relationship between human behavior and 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.

Missing Moonstones

In the 1970s, the Richard Nixon administration distributed rocks brought from the lunar surface during the Apollo 11 and Apollo 17 missions to the leaders of 270 countries.

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 ran a covert operation called " Moon eclipse to put an end to the illegal sale of these stones.

What was all this fuss about? A pea-sized piece of moon rock 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 UN Treaty on space property In 1967, according to which "no country" can claim the solar system, Nevada resident Dennis Hope wrote to the UN and announced the right to private property. They didn't answer him.

But why wait? Hope opened a lunar embassy and began selling one-acre lots for $19.99 each. For the UN solar system is almost the same as the world's oceans: outside the economic zone and belonging to every inhabitant of the Earth. Hope claimed to have sold off-world properties to celebrities and three former presidents USA.

It is not clear whether Dennis Hope really does not understand the wording of the treaty, or whether he is trying to force the legislature to do legal assessment their actions so that the development of celestial resources can begin under more transparent legal conditions.

Sources:

Why do we only see one side of the moon?

The Moon floats high in the sky, bright, beautiful, with dark spots on a shiny disk. On a full moon, it resembles someone's round, good-natured, slightly mocking face. We always see her like this. And before us, for thousands of years, people looked at the exact same Moon and dark spots were distributed on it in the same way, which make it look like a human face. For thousands of years, people have been observing the changes in her bright face - from the thin sickle of a newborn month to the full radiance of her disk. Meanwhile, the Moon is a ball, the same as other planets, including our Earth, on which we live. But the moon never shows us its other side, we don't see it. Why?

The moon rotates on its axis and at the same time makes its way around the earth, because it is a satellite of the earth.

In twenty-nine and a half days, it makes its revolution around the Earth, and ... it takes the same amount of time to turn around its axis - it makes this revolution so slowly. And that's the whole point. That is why we always see only one side of it.

But how does it happen anyway? To make this clearer to you, let's do a little experiment. Take some small table (if there is no table - a chair or something else that is more convenient for you, what will be at hand). This chair will be an imaginary Earth, and you yourself will be the Moon, which wraps around the Earth. Start moving around the table, staying facing it all the time. At the beginning of your movement, for example, you saw a window in front of you, but then, as you make your circle around the table (that is, the Earth), this window will be behind you, and only at the end of the path you will see it again . This will only confirm that you have turned not only around the table, but also around yourself, your axis.

So is the Moon. It makes a revolution around the Earth and at the same time around its own axis.

But everyone now knows that we still saw the far side of the moon! How did it happen? Do you remember? .. However, no, you don’t remember this: in those years you were still too small! And this happened in 1959, when Soviet scientists launched an automatic station towards the Moon, which flew around our satellite and transmitted images from its other side to us on Earth. And people all over the world saw the far side of the moon for the first time!

And that's not all. A few years later, Soviet scientists again sent an automatic station towards the Moon, and this time again photographs were taken and sent to Earth. Thanks to the images, scientists then compiled the first map of both sides of the lunar surface, and then a new color map of the Moon with lunar seas, mountain ranges, the most important peaks, ring crater mountains, circuses.

While I was writing these pages, one piece of news followed another. Before I had time to tell you about the new color map, an amazing event took place: in February 1966, the world's first automatic station, our Soviet one, landed on the Earth's satellite! She made, as scientists say, a soft landing - this means that she landed on the moon smoothly, without breaking the equipment.

Having gently landed on the moon, the automatic station immediately began to work hard - it sent more and more pictures of the lunar surface, and these pictures were taken at close range. But this is extremely important! The images were large, accurate: scientists simply pounced on these amazing documents, carefully examined them; now they saw what the surface of the moon is like, what is on it, asserted or, on the contrary, changed their points of view about the lunar surface.

"Luna-9" made a soft landing on our satellite - the Moon. And shortly after that, in March 1966, Luna 10 was launched.

She began to make flights around the Moon, that is, she became her artificial satellite, and the Luna-10 instruments sent messages to Earth that scientific researchers needed in order to better know our celestial neighbor.

"Luna-10" made its endless flight around the Moon, so close, familiar, and in the early days, the whole world could hear the melody of the Communist anthem "The Internationale" coming from it.

After "Luna-10" there were also "Luna-11", and "Luna-12", and "Luna-14", and "Luna-16" ... All the time our messengers soar into outer space, they pave the first paths to our heavenly neighbor. And always the most difficult and most important thing is what is done for the first time!

However, the news of recent years is amazing! American astronauts, on the Apollo 11 spacecraft, Neil Armstrong, Edwin Aldrin and Michael Collins were the first to fly to the moon in July 1969, two of them, Neil Armstrong and Edwin Aldrin, set foot on its surface, the third, Michael Collins, was waiting them by making circles around the moon.

The names of these cosmonauts will go down in history in the same way as the name of our glorious Gagarin, who was the first to go into space and see our planet Earth from the outside.

And a very special place in the study of our celestial neighbor is occupied by the amazing apparatus "Lunokhod-1", delivered to the Moon in November 1970. He worked hard there, doing the work of exploring the lunar surface for a man. This amazing apparatus worked only on a lunar day, when it could charge its batteries from the energy of the sun. And on a moonlit night, he rested, as they affectionately said about him: he slept.

Really, it all looks like a fairy tale.

And it may well happen that during the time this book is being printed, new amazing events will occur and we will have to expand this chapter, although at the beginning we were going to tell only about one thing: why we do not see the far side of the moon.

Falling stars

I don’t know about you, but I have always loved looking at the sky on quiet, cloudless evenings. I loved to look for constellations, some were difficult to find, and others were easy, such as Ursa Major or Cassiopeia.

On dark August nights, when the sky turns completely black, a wide bright road of stars is clearly visible - Milky Way. I stood with my head thrown back for a long time, so that my neck ached, and admired dark skies, stars and silver moon.

But… what is it? A fiery dot traced the sky and went out. "A star has fallen," say those who saw it.

Star? No, it's something completely different, because the stars don't fall. These are small pebbles, dust particles that are worn in outer space and with terrible speed, attracted by the Earth, they fly into the atmosphere and burn up! We see this short flash and say: the star has fallen!

Little heavenly guests that burn up somewhere very high above the Earth are called meteors.

In August, October and November, the Earth, during its journey around the Sun, encounters especially a lot of cosmic dust, clouds, and pebbles. That is why at this time you can often see fiery flashes in the sky. This means that the Earth has met on its way a whole swarm of meteors and "space debris", and it flares up, flying into our atmosphere.

It happens that dozens of meteors flash at once in the sky and " star Rain continues until the Earth passes the meteor shower.

Starry rain fell over Moscow more than twenty years ago, in 1946. Only we could not observe it, because the sky was covered with clouds. It was very annoying!

And there are not rains, but simply star showers! But this happens very rarely. At the end of the last century, several such showers were shed, they could be observed both in the sky of America and over Europe. It was a magnificent fireworks display arranged by nature itself.

Star showers, and especially star showers, are an exceptional phenomenon. You can live your life and not see them. On the other hand, we can always observe lonely fiery dots, flashing and fading in the dark August sky, lonely "shooting stars". Just remember: these are not stars - stars never fall! This is space dust. Dust particles flare up from strong air resistance when they fly into earth's atmosphere. Flash on and off!

Why is it day and night?

I woke up at eight o'clock. Outside the window - the pace of the night! I remembered that today is December 22, the day winter solstice when we, in the Northern Hemisphere, have the most long night of the year and the shortest day.

That year there was no snow for a long time, or rather, it was, only it didn’t lie for a long time - it melted. Mud, puddles, piercing wind and darkness - at four o'clock in the afternoon it is already necessary to turn on the light!

I do not like this time of the year, the time of a very late, protracted autumn, and I always look forward to the cherished December 22, when the sun, as they say, turns to summer, and winter to frost. After the winter solstice, the days begin to gradually arrive, and the night shortens, at first for some minute, and you look - in a month and an hour will increase. But winter comes into its own: frosts crackle, snow falls, and twilight turns blue, almost purple ...

Day and night… Change of light and darkness… The most ordinary, most constant, unchanging phenomenon of nature, it goes on in an eternal routine. But why is this happening?

Once upon a time, in ancient times, not only children, but also adults asked themselves this question and did not find the right answer to it. Thousands of years passed before man understood and explained this phenomenon.

Eternal companion of the Earth, surrounded by romantic stories and scientific mysteries, the Moon is shown as a fixed side 100% of the time. But why is the other side of the Moon not visible, are there mystical facts in the theory, or is it easy to explain the process from the point of view of physics and astronomy?

How is the turnover?

The Internet is full of photos and videos compiled from them throughout the year, which show exactly how we see the moon. The principles of celestial mechanics will help explain the phenomenon of one side of the cosmic body.

The planet rotates around its own axis and the Sun, and for the Moon, the "sun" becomes the Earth. It revolves around the personal axis and the planet. The speed of a celestial body going around the Earth is 100% the same as the speed of rotation around its own axis.

This means that the Moon rotates 100% synchronously around the planet and around the axis. This was not always the case, and the process of rotation at first looked different. Under the influence of the Earth's gravity and the tides, the planet slowly adjusted the satellite to its own characteristics. This is the reason why the far side of the Moon is not visible.

Practical rotation example

To understand exactly how the turnover occurs, you can conduct a small experiment:

1. Place a chair in the center of the room. This is Earth.
2. Stand at arm's length and place your fingertips in the center of the object. You are the Moon.
3. Start moving so that your fingers do not move. Make a full circle.

Did you notice that you were on one side of the object during the experiment? This also happens with the Earth's satellite.

Do we see exactly half from Earth?

The celestial body makes a complete revolution in only 27 days 7 hours and 43.1 minutes of time. If you look at the video, where the process is recorded for a whole year, it becomes clear that we see more than 50% of the Moon. On the opposite side remains inaccessible 41% of the surface.

The rotation of the satellite does not always occur at the same speed. Lunar librations occur - when the satellite approaches the Earth at a minimum distance, the speed increases. As the lunar orbit gets farther, the speed slows down. It is also important to understand that they rotate celestial bodies along an ellipsoidal path.

More than 4 billion years ago, the Earth and its satellite formed, they rotated faster, and their speeds were different. Now big planet adjusted the small one for herself, and this main reason Why is the far side of the moon not visible to the eye.