In the night sky, we see the only satellite of the Earth that accompanies our planet. We usually only see it at night. But why does the Moon not fall to the Earth, what keeps it in the sky?
Scientific explanation of the question "Why does the moon not fall?"
The moon is not permanently attached to the earth. It revolves around our planet. Therefore, on different days we see different forms of our natural satellite. Sometimes he appears in a cloudless sky since the evening, and sometimes late at night. We say that the month rises and sets, that today is a full moon, and in 20 days there will be a new moon. But answering the question "Why does the moon not fall" is difficult. Indeed, according to Newton's law, an attractive force acts on any body, and it must fall.
The moon is influenced by the earth and the sun. They pull her in two directions. But the attraction from the main luminary is much stronger than from our planet. Therefore, the Moon and the Earth revolve around the center of the universe, but at the same time are next to each other. If only the Sun acted on the Moon, then it would move along a route with strongly concave points. But our planet also affects it. Its action is much smaller compared to the action of a powerful luminary, but the Earth is closer to the month. Therefore, our planet aligns the trajectory of its satellite, changing it from time to time.
It turns out that the Moon is attracted by two large celestial bodies. But that's not enough to keep her from falling. She doesn't fall because she moves. Its speed is 1 km/sec. This is enough not to fall, but not enough not to leave its orbit. If the night luminary can stop something, then it will fall to the earth's surface.
The answer to the question "Why does the moon not fall to the Earth?"
The attraction of two bodies, movement in space - all this can be easily modeled. Try it and you will understand why the Moon cannot fall to the Earth. The answer can be obtained from a small and very simple experience. Take an object that is convenient to fasten on a thread. Tie it well and start twisting. Here is your item spinning pretty fast. It doesn't fall, it doesn't fly anywhere. The thread is the force of attraction. Your hand is the earth. The object on the thread is the Moon. The movement does not allow it to fall, leave the orbit, and the thread does not fly away from you. If the thread breaks, the object will fly off. So it is with Luna. When the force of gravity of the planet weakens, the night star will fly away into the distant Cosmos.
Another experiment will help to understand the way the satellite of our planet moves. Take an apple. Unclench your hand - it will fall. Newton's force works. Take the apple again and try to throw it parallel to the surface. The apple will fly by for a while and then fall down. What if we throw an apple on a big globe? Then parallel to it? Then the apple will fly over the globe and fall in another place. And if the globe attracts, then the apple will fly parallel to its surface.
Why doesn't the moon fall on the sun?
If the sun stronger than the earth, then why doesn't the moon fall on ? Why is the power of the center of the Universe not able to attract this night luminary? Capable. The sun's attraction is twice as strong as the earth's. But our planet does not allow the Moon to fall on the Sun. Although she draws the moon to her weaker, she is next to her. This proximity compensates for the influence of the Sun. And the moon does not fly away from its orbit to fall on the solar surface.
Balances the two different forces attraction distance. But scientists prove that the moon is getting further away from us every year. A month moves away from the Earth by 3-4 cm per year. This is imperceptible on a scale human life. However, the farther the satellite moves away from the Earth, the less force our planet will exert on it, and the influence of the Sun will increase.
So far, the only satellite of our planet revolves around us, and the Earth, together with its satellite, revolves around the Sun. The solar force goes to ensure that these two bodies do not move in a straight line, but go along a curved orbit. For more power, the daylight is not enough.
Why doesn't the moon fall to earth? Short answer
3 points of answer “Why doesn’t it fall to Earth?”:
1. She is held by gravity. If it does not exist, then the Moon will fly away into open space.
2. From falling to the Earth, the Moon is protected by solar attraction. The strength of this luminary is twice as strong, but our satellite is closer to its planet. This equalizes the impact of two large bodies.
3. Movement keeps the moon from falling. If it stops, it will fall to the ground.
Even if we assume that the night luminary stopped and began to fall on the earth's surface, then a huge energy will be released that will destroy the month. As a result, our satellite will cease to be a solid body.
Relevance:
On April 12, our country remembers a grandiose event - a manned flight into space. At the lessons, we also discussed the topic of space, drew pictures. And the teacher asked us to prepare interesting reports about space. Therefore, I chose this particular topic, since it is interesting to me myself. And on the eve of this Cosmonautics Day holiday, this is relevant for us, I think that you will also be interested.
My assumptions:
At home, I took out the encyclopedia "Heavenly Bodies" and began to read. Then I asked myself, maybe the moon could fall on us? I replied that, probably, the Moon would fall if it approached the Earth. Or maybe something keeps her with the Earth, so she does not fall and does not fly away.
Purpose and objectives of my work:
I decided to study the literature in more detail, how the Moon was formed, how it affects the Earth, what connects it with the Earth, and why the Moon does not fly into space and does not fall to the Earth. And here's what I found out.
Introduction
In astronomy, a satellite is a body that revolves around a large body and is held by the force of its attraction. The Moon is the Earth's satellite. Earth is a satellite of the Sun. The Moon is a hard, cold, spherical celestial body, which is 4 times smaller than the Earth.
The Moon is the closest celestial body to Earth. If it were possible, then a tourist would walk to the moon for 40 years
The Earth-Moon system is unique in the solar system, since no planet has such a large satellite. The Moon is the only satellite of the Earth.
It is better visible to the naked eye than any planet through a telescope. Our satellite is fraught with many mysteries.
The moon is so far the only cosmic body that has been visited by man. The Moon revolves around the Earth in the same way that the Earth revolves around the Sun (see Fig. 1).
The distance between the centers of the Moon and the Earth is approximately 384467 km.
What does the moon look like?
The Moon is not at all like the Earth. There is no air, no water, no life. The concentration of gases near the surface of the moon is equivalent to a deep vacuum. Due to the lack of atmosphere, its gloomy dusty expanses heat up to + 120 ° C during the day and freeze at night or just in the shade up to - 160 ° C. The sky on the moon is always black, even during the day. The huge disk of the Earth looks from the Moon more than 3.5 times than the Moon from the Earth, and hangs almost motionless in the sky (see Fig. 2).
The entire surface of the moon is pitted with funnels, which are called craters. You can see them by looking at the moon on a clear night. Some craters are so large that they could fit a huge city. There are two main options for the formation of craters - volcanic and meteorite.
The lunar surface can be divided into two types: very old mountainous terrain (lunar mainland) and relatively smooth and younger lunar seas.
The lunar seas, which make up approximately 16% of the entire surface of the moon, are huge craters resulting from collisions with celestial bodies that were later flooded with liquid lava. The lunar seas were given names: the Sea of Crises, the Sea of Abundance, the Sea of Tranquility, the Sea of Rains, the Sea of Clouds, the Sea of Moscow and others.
Compared to the Earth, the Moon is very small. The radius of the moon is 1738 km, the volume of the moon is 2% of the volume of the Earth, and the area is approximately 7.5%
How was the Moon formed?
The Moon and the Earth are almost the same age. Here is one of the versions of the formation of the moon.
1. Shortly after the formation of the Earth, a huge celestial body crashed into it.
2. From the impact, it shattered into many fragments.
3. Under the influence of gravity (attraction) of the Earth, the fragments began to revolve around it.
4. Over time, the fragments gathered together, and the Moon was formed from them.
Moon phases
The moon changes its appearance every day. First, a narrow crescent, then the Moon grows fat and after a few days becomes round. Some more days full moon gradually becomes smaller and smaller and again becomes like a sickle. The crescent moon is often called the month. If the sickle is turned with a convexity to the left, like the letter “C”, then the Moon is said to be “aging”. After 14 days and 19 hours after the full moon, the old month will disappear completely. The moon is not visible. This phase of the moon is called the “new moon”. Then, gradually, the Moon from a narrow crescent turned to the right turns back into the full Moon.
For the moon to “grow up” again, the same period of time is required: 14 days and 19 hours. Changing the appearance of the moon, i.e. the change of lunar phases, from full moon to full moon, occurs every four weeks, more precisely for 29 and a half days. This is a lunar month. It served as the basis for compiling the lunar calendar. During the full moon, the moon is turned to the Earth with the illuminated side, and during the new moon, the unlit side. Turning around the Earth, the moon turns to it either as a fully illuminated surface, or as a partially illuminated surface, or as a dark one. That is why the appearance of the Moon is constantly changing during the month.
Ebb and flow
The gravitational forces between the Earth and the Moon cause some interesting effects. The most famous of them is the tides of the sea. The difference between the levels of high and low tide in the open spaces of the ocean is small and amounts to 30–40 cm. However, near the coast, due to the incursion of a tidal wave onto a solid bottom, the tidal wave increases its height in the same way as ordinary wind waves of the surf.
Given the direction of rotation of the Moon around the Earth, it is possible to form a picture of the tidal wave following the ocean. The maximum amplitude of a tidal wave on Earth is observed in the Bay of Fundy in Canada and is 18 meters.
Moon exploration
The moon has attracted the attention of people since ancient times. The invention of telescopes made it possible to distinguish finer details of the relief (surface shape) of the Moon. One of the first lunar maps was compiled by Giovanni Riccioli in 1651, he also gave names to large dark areas, calling them “seas”, which we still use today. In 1881 Jules Janssen compiled a detailed "Photographic Atlas of the Moon".
With the advent of the space age, our knowledge of the moon has increased significantly. The Moon was first visited by the Soviet spacecraft Luna-2 on September 13, 1959.
For the first time I was able to look at reverse side The moon in 1959, when the Soviet Luna-3 station flew over it and photographed part of its surface invisible from the Earth.
The American program of manned flight to the moon was called "Apollo".
The first landing took place on July 20, 1969, and the first person to set foot on the surface of the moon was the American Neil Armstrong. Six expeditions have visited the Moon, but the last time it was back in 1972, since the expeditions are very expensive. Each time, two people landed on it, who spent up to three days on the moon. New expeditions are currently being prepared.
Why doesn't the moon fall to the earth?
The moon would instantly fall to the Earth if it were stationary. But the Moon does not stand still, it revolves around the Earth.
When we throw an object, such as a tennis ball, gravity pulls it towards the center of the earth. Even a tennis ball thrown at high speed will still fall to the ground, but the picture will change if the object is much further away and moving much faster.
My experience:
I asked this question to my dad and he explained it to me on simple example. We tied an ordinary eraser to a thread. Imagine that you are the Earth, and the eraser is the moon, and start spinning it. The eraser on the thread will literally break out of your hand, but the thread will not let it go. The moon is so far away and moving so fast that it never falls in the same direction. Even falling constantly, the moon will never fall to the earth. Instead, it moves around the earth in a constant path.
If we rotate the eraser very strongly, the thread will break, and if we rotate it slowly, the eraser will fall.
We conclude: if the moon moved even faster, then it would overcome the gravity of the earth and fly away into space, if the moon moved more slowly, gravity would pull it to the earth. This precise balance of gravity creates what we call an orbit, where the smaller celestial body is constantly revolving around the larger one.
The force that keeps the Moon from “running away” as it spins is the Earth's gravity. And the force that prevents the Moon from falling to the Earth is the centrifugal force that occurs when the Moon rotates around the Earth.
Circulating around the Earth, the Moon moves in orbit at a speed of 1 km / s, that is, slowly enough not to leave its orbit and “fly away” into space, but also fast enough not to fall to Earth.
By the way...
You will be surprised, but in fact the Moon ... is moving away from the Earth at a speed of 3-4 cm per year! The movement of the Moon around the Earth can be imagined as a slowly unwinding spiral. The reason for such a trajectory of the Moon is the Sun, which attracts the Moon 2 times stronger than the Earth.
Why then does the moon not fall on the sun? But because the Moon, together with the Earth, revolves, in turn, around the Sun, and the attractive action of the Sun is spent without a trace on constantly transferring both of these bodies from a direct path to a curved orbit.
- The moon itself does not glow, it only reflects the falling on it sunlight;
- The moon rotates around its axis in 27 Earth days; during the same time it makes one revolution around the Earth;
- The moon, revolving around the earth, always faces us on one side, its reverse side remains invisible to us;
- The moon, moving along its orbit, gradually moves away from the Earth by about 4 cm per year.
- The force of gravity on the Moon is 6 times less than on Earth.
Therefore, it is much easier for a rocket to take off from the Moon than from the Earth.
It is possible that soon on distant interplanetary flights spaceships will be sent not from the Earth, but from the Moon.
Since the beginning of this century, China has announced its readiness to explore the moon, as well as to build several manned lunar bases there. After this statement, the space organizations of the leading countries, and in particular the USA (NASA) and ESA (European Space Agency) launched their space programs again.
What will come of it?
Let's see in 2020. It was for this year that George Bush planned to land people on the moon. This date is ten years ahead of China, since their space program said that the creation of habitable lunar bases and landing people on them would take place only in 2030.
The moon is the most studied celestial body, but for a person it still holds a lot of mysteries: perhaps it is the base of extraterrestrial civilizations, perhaps life on Earth would be completely different if there was no moon, perhaps in the future a person will settle on the moon ...
Conclusions:
So, we found out that the Moon is a natural satellite of the Earth, it revolves around our planet and, together with the Earth, moves in orbit around the Sun;
- the question of the origin of the moon is still controversial;
The changes in the shape of the moon are called phases. They exist only for us
One of my assumptions turned out to be correct, the Moon is really holding something, and this is the Earth's gravity and centrifugal force.
And my other assumption that the Moon will fall if it approaches the Earth is not entirely correct. The moon will fall to the Earth when the moon stops rotating, is stationary, then the centrifugal force will not work.
Studying encyclopedias and the Internet, I learned a lot of new and interesting things. I will definitely share these discoveries with my classmates in the lesson about the world around us.
We managed to unravel some of the mysteries of the Moon, but this did not make it less interesting and attractive!
References:
1. “Space. Supernova Atlas of the Universe”, M., “Eksmo”, 2006.
2. New school encyclopedia"Heavenly bodies", M., "Rosmen", 2005
3. "Why" Children's Encyclopedia, M., "Rosmen", 2005
4. “What is it? Who it?" children's encyclopedia, M.,” Pedagogy -
Press" 1995
5. Internet - reference books, pictures about space.
Completed: 3B class student
Khaliullin Ildar
Supervisor: Sakaeva G.Ch.
MOU secondary school №79, Ufa
Everything in this world is attracted to everything. And for this you do not need to have any special properties ( electric charge, participate in the rotation, have a size no less than some.). It is enough just to exist, as there is a person or the Earth, or an atom. Gravity, or as physicists often say, gravity, is the most universal force. And yet: everything is attracted to everything. But how exactly? By what laws? Surprising as it may seem, this law is the same, and moreover, it is the same for all bodies in the Universe - both for stars and for electrons.
1. Kepler's laws
Newton argued that between the Earth and all material bodies there is a gravitational force, which is inversely proportional to the square of the distance.
In the 14th century, an astronomer from Denmark, Tycho Brahe, observed the movement of the planets for almost 20 years and recorded their positions, and was able to determine their coordinates at various points in time with the greatest possible accuracy at that time. His assistant, mathematician and astronomer Johannes Kepler, analyzed the teacher's notes and formulated three laws of planetary motion:
Kepler's first law
Every planet solar system revolves around an ellipse with the Sun at one of its foci. The shape of the ellipse, the degree of its similarity with the circle will then characterize the ratio: e=c/d, where c is the distance from the center of the ellipse to its focus (half the interfocal distance); a - semi-major axis. The value of e is called the eccentricity of the ellipse. For c = 0 and e = 0, the ellipse turns into a circle with radius a.
Kepler's second law (Law of areas)
Each planet moves in a plane passing through the center of the Sun, and the area of the sector of the orbit, described by the radius vector of the planets, changes in proportion to time.
In relation to our solar system, two concepts are associated with this law: perihelion - the point of the orbit closest to the Sun, and aphelion - the most distant point of the orbit. Then it can be argued that the planet moves around the Sun non-uniformly: having a linear velocity at perihelion is greater than at aphelion.
Every year at the beginning of January, the Earth, passing through perihelion, moves faster; therefore, the apparent movement of the Sun along the ecliptic to the east also occurs faster than the average for the year. In early July, the Earth, passing aphelion, moves more slowly, therefore, the movement of the Sun along the ecliptic slows down. The law of areas indicates that the force that controls the orbital motion of the planets is directed towards the Sun.
Kepler's Third Law (Harmonic Law)
Kepler's third or harmonic law relates the average distance of a planet from the Sun (a) to its orbital period (t):
where indices 1 and 2 correspond to any two planets.
Newton took over from Kepler. Fortunately, there are quite a few archives and letters left from England in the 17th century. Let's follow Newton's reasoning.
I must say that the orbits of most planets differ little from circular ones. Therefore, we will assume that the planet does not move along an ellipse, but along a circle of radius R - this does not change the essence of the conclusion, but greatly simplifies mathematics. Then Kepler's third law (it remains in force, because the circle is special case ellipse) can be formulated as follows: the square of the time of one revolution in orbit (T2) is proportional to the cube of the average distance (R3) from the planet to the Sun:
T2=CR3 (experimental fact).
Here C is a certain coefficient (the constant is the same for all planets).
Since the time of one revolution T can be expressed in terms of average speed of the planet's orbit v: T=2(R/v, then Kepler's third law takes the following form:
Or after the reduction 4(2 /v2=CR.
Now we take into account that, according to Kepler's second law, the movement of the planet along a circular trajectory occurs uniformly, i.e., with a constant velocity. We know from kinematics that the acceleration of a body moving in a circle at a constant speed will be purely centripetal and equal to v2/R. And then the force acting on the planet, according to Newton's second law, will be equal to
Let us express the ratio v2/R from Kepler's law v2/R=4(2/СR2) and substitute it into Newton's second law:
F \u003d m v2 / R \u003d m4 (2 / СR2 \u003d k (m / R2), where k \u003d 4 (2 / С is a constant value for all planets.
So, for any planet, the force acting on it is directly proportional to its mass and inversely proportional to the square of its distance from the Sun:
The sun, the source of the force acting on the planet, follows from Kepler's first law.
But if the Sun attracts the planet with force F, then the planet (according to Newton's third law) must also attract the Sun with the same force F. Moreover, this force by its nature is no different from the force from the Sun: it is also gravitational and, as we have shown, it should also be proportional to the mass (this time of the Sun) and inversely proportional to the square of the distance: F=k1(M/R2), here the coefficient k1 is different for each planet (maybe it even depends on its mass!) .
Equating both gravitational forces, we get: km=k1M. This is possible provided that k=(M, and k1=(m, i.e. at F=((mM/R2), where (- constant is the same for all planets.
Therefore, the universal gravitational constant (cannot be any - with the units of magnitude we have chosen - only the one chosen by nature. Measurements give an approximate value (= 6.7 x10-11 N. m2 / kg2.
2. Law of gravity
Newton received a remarkable law describing the gravitational interaction of any planet with the Sun:
All three Kepler's laws turned out to be consequences of this law. It was a colossal achievement to find (one!) a law governing the movement of all planets in the solar system. If Newton had limited himself to just this, we would still remember him when studying physics at school and would call him an outstanding scientist.
Newton was a genius: he suggested that the same law governs the gravitational interaction of any bodies, he describes the behavior of the moon revolving around the earth, and an apple falling to the earth. It was an amazing thought. After all, there was a general opinion - celestial bodies move according to their (heavenly) laws, and earthly bodies - according to their own, “worldly” rules. Newton assumed the unity of the laws of nature for the entire universe. In 1685, I. Newton formulated the law of universal gravitation:
Any two bodies (more precisely, two material points) are attracted towards each other with a force directly proportional to their masses and inversely proportional to the square of the distance between them.
The law of gravity is one of best examples showing what a person is capable of.
The gravitational force, unlike friction and elastic forces, is not a contact force. This force requires two bodies to touch in order for them to interact gravitationally. Each of the interacting bodies creates a gravitational field in the entire space around itself - a form of matter through which the bodies gravitationally interact with each other. The field created by some body manifests itself in that it acts on any other body with a force determined by the universal law of gravity.
3. Movement of the Earth and the Moon in space.
The Moon, a natural satellite of the Earth, in the process of its movement in space is influenced mainly by two bodies - the Earth and the Sun. We calculate the force with which the Sun attracts the Moon, applying the law of universal gravitation, we get that the solar attraction is twice as strong as the earth's.
Why doesn't the moon fall on the sun? The fact is that both the Moon and the Earth revolve around a common center of mass. The common center of mass of the Earth and the Moon revolves around the Sun. Where is the center of mass of the Earth-Moon system? The distance from the Earth to the Moon is 384,000 km. The ratio of the mass of the Moon to the mass of the Earth is 1:81. The distances from the center of mass to the centers of the Moon and the Earth will be inversely proportional to these numbers. Dividing 384,000 km by 81, we get approximately 4,700 km. This means that the center of mass is located at a distance of 4700 km from the center of the Earth.
* What is the radius of the Earth?
* About 6400 km.
* Therefore, the center of mass of the Earth-Moon system lies inside the globe. Therefore, if you do not pursue accuracy, you can talk about the revolution of the Moon around the Earth.
Movements of the Earth and the Moon in space and their change mutual position in relation to the Sun are shown in the diagram.
With a two-fold predominance of solar attraction over the earth's, the curve of the motion of the Moon should be concave with respect to the Sun at all its points. The influence of the nearby Earth, which significantly exceeds the mass of the Moon, leads to the fact that the magnitude of the curvature of the lunar heliocentric orbit changes periodically.
The moon revolves around the earth, held by the force of gravity. With what force does the earth pull the moon?
This can be determined by the formula expressing the law of gravity: F=G*(Mm/r2) where G is the gravitational constant, Mm are the masses of the Earth and the Moon, r is the distance between them. Having made the calculation, we came to the conclusion that the Earth attracts the Moon with a force of about 2-1020 N.
The entire action of the force of attraction of the Moon by the Earth is expressed only in keeping the Moon in orbit, in imparting centripetal acceleration to it. Knowing the distance from the Earth to the Moon and the number of revolutions of the Moon around the Earth, Newton determined the centripetal acceleration of the Moon, which resulted in the number already known to us: 0.0027 m/s2. Good agreement between the calculated value of the centripetal acceleration of the Moon and its actual value confirms the assumption that the force holding the Moon in orbit and the force of gravity are of the same nature. The moon in orbit could be held by a steel rope with a diameter of about 600 km. But, despite such a huge force of attraction, the Moon does not fall to the Earth.
The Moon is removed from the Earth at a distance equal to about 60 Earth radii. Therefore, Newton reasoned. The Moon, falling with such an acceleration, should approach the Earth in the first second by 0.0013 m. But the Moon, in addition, moves by inertia in the direction instantaneous speed, i.e., along a straight line, tangent at a given point to its orbit around the Earth
Moving by inertia, the Moon should move away from the Earth, as the calculation shows, in one second by 1.3 mm. Of course, such a motion, in which in the first second the Moon would move along the radius to the center of the Earth, and in the second second - tangentially, does not really exist. Both movements add up continuously. As a result, the Moon moves along a curved line close to a circle.
Circulating around the Earth, the Moon moves in orbit at a speed of 1 km / s, that is, slowly enough not to leave its orbit and "fly away" into space, but also fast enough not to fall to Earth. We can say that the Moon will fall to the Earth only if it does not move in orbit, i.e. if external forces(some kind of cosmic hand) stop the Moon in its orbit, then it will naturally fall to the Earth. However, in this case, so much energy will be released that talking about the fall of the Moon to Earth, as solid body do not have to. From all of the above, we can conclude.
The moon is falling, but it cannot fall. And that's why. The motion of the Moon around the Earth is the result of a compromise between the two "desires" of the Moon: to move by inertia - in a straight line (due to the presence of speed and mass) and to fall "down" to the Earth (also due to the presence of mass). You can say this: world law gravitation calls the Moon to fall to the Earth, but Galileo's law of inertia "persuades" it to pay no attention to the Earth at all. The result is something in between - an orbital movement: a constant, without end, fall.
The article talks about why the Moon does not fall to the Earth, the reasons for its movement around the Earth and some other aspects of the celestial mechanics of our solar system.
The beginning of the space age
The natural satellite of our planet has always attracted attention. In ancient times, the Moon was the object of worship of some religions, and with the invention of primitive telescopes, the first astronomers could not tear themselves away from contemplating the majestic craters.
A little later, with the discovery in other areas of astronomy, it became clear that not only our planet, but also a number of others have such a celestial satellite. And Jupiter has 67 of them! But ours is the leader in size in the entire system. But why doesn't the moon fall to the earth? What is the reason for its movement along the same orbit? We will talk about this.
Celestial mechanics
First, you need to understand what orbital movement is and why it happens. According to the definition used by physicists and astronomers, an orbit is a movement into another object that is much larger in mass. For a long time it was believed that the orbits of the planets and satellites have a circular shape as the most natural and perfect, but Kepler, after unsuccessful attempts to apply this theory to the movement of Mars, rejected it.
As is known from the course of physics, any two objects experience mutual so-called gravity. The same forces affect our planet and the moon. But if they are attracted, then why does the moon not fall to the Earth, as would be the most logical thing?
The thing is that the Earth does not stand still, but moves around the Sun in an ellipse, as if constantly “running away” from its satellite. And that, in turn, have an inertial speed, which is why it travels again in an elliptical orbit.
The simplest example that can explain this phenomenon is a ball on a rope. If you spin it, it will hold the object in one plane or another, and if you slow down, it will not be enough and the ball will fall. The same forces act and the Earth drags it along, not allowing it to stand still, and the centrifugal force developed as a result of rotation holds it, preventing it from approaching a critical distance.
If the question of why the Moon does not fall to the Earth is given an even simpler explanation, then the reason for this is the equal interaction of forces. Our planet attracts the satellite, forcing it to rotate, and the centrifugal force, as it were, repels.
Sun
Such laws apply not only to our planet and satellite, they are subject to all the rest. In general, gravity is very interesting topic. The movement of the planets around is often compared to a clockwork, it is so accurate and verified. And most importantly, it is extremely difficult to break it. Even if several planets are removed from it, the rest with a very high probability will rebuild into new orbits, and there will be no collapse with a fall on the central star.
But if our luminary has such a colossal gravitational effect even on the most distant objects, then why does the Moon not fall on the Sun? Of course, the star is at a much greater distance than the Earth, but its mass, and hence gravity, is an order of magnitude higher.
The thing is that its satellite also moves in orbit around the Sun, and the latter does not act separately on the Moon and the Earth, but on their common center of mass. And on the Moon there is a double influence of gravity - stars and planets, and after it the centrifugal force that balances them. Otherwise, all satellites and other objects would have burned out long ago in a hot luminary. That is the answer to frequently asked question about why the moon does not fall.
Sun movement
Another fact worth mentioning is that the Sun also moves! And along with it, our entire system, although we are accustomed to believing that outer space is stable and unchanging, with the exception of the orbits of the planets.
If you look more globally, within the framework of systems and their entire clusters, you can see that they also move along their trajectories. In this case, the Sun with its "satellites" revolves around the center of the galaxy. If you conditionally imagine this picture from above, then it looks like a spiral with many branches, which are called galactic arms. In one of these arms, along with millions of other stars, our Sun also moves.
A fall
But still, if you ask such a question and dream up? What conditions are needed under which the Moon will crash into the Earth or go on a journey to the Sun?
This can happen if the satellite stops rotating around the main object and the centrifugal force disappears, also if something changes its orbit and adds speed, for example, a collision with a meteorite.
Well, it will go to the star, if purposefully somehow stop its movement around the Earth and give the initial acceleration to the luminary. But most likely, the Moon will simply gradually rise into a new curved orbit.
To summarize: the Moon does not fall to the Earth, because, in addition to the attraction of our planet, it is also affected by the centrifugal force, which, as it were, repels it. As a result, these two phenomena balance each other, the satellite does not fly away and does not crash into the planet.
The moon would instantly fall to the Earth if it were stationary. But the Moon does not stand still, it revolves around the Earth.
You can see for yourself by doing a simple experiment. Tie a thread to the eraser and start unwinding it. The eraser on the thread will literally break out of your hand, but the thread will not let it go. Now stop spinning. The eraser will immediately fall off.
An even more illustrative analogy is the ferris wheel. People do not fall out of this carousel when they are in highest point, even though they are upside down, because the centrifugal force that pushes them outward (pulls them towards the seat) is greater than the Earth's gravity. The speed of rotation of the ferris wheel is specially calculated, and if the centrifugal force were less than the force of gravity of the Earth, it would end in disaster - people would fall out of their cabins.
The same is true of the Moon. The force that keeps the Moon from "running away" as it spins is Earth's gravity. And the force that prevents the Moon from falling to the Earth is the centrifugal force that occurs when the Moon rotates around the Earth. Circulating around the Earth, the Moon moves in orbit at a speed of 1 km / s, that is, slowly enough not to leave its orbit and “fly away” into space, but also fast enough not to fall to Earth.
By the way...
You will be surprised, but in fact the Moon ... is moving away from the Earth at a speed of 3-4 cm per year! The movement of the Moon around the Earth can be imagined as a slowly unwinding spiral. The reason for such a trajectory of the Moon is the Sun, which attracts the Moon 2 times stronger than the Earth.
Why then does the moon not fall on the sun? But because the Moon, together with the Earth, revolves, in turn, around the Sun, and the attractive action of the Sun is spent without a trace on constantly transferring both of these bodies from a direct path to a curved orbit.
